Grimes was cast after producers saw her acting a dramatic scene which they believe "she just killed. She is based in part on Brenda Walsh from the original series. She lives with her parents, Harry and Debbie, her adopted brother Dixon whom she considers her best friend and her grandmother Tabitha. She struggles to find her place in California and to maintain her sweet nature. She and Ethan had dated after he broke up with Naomi, but concealed it so that Naomi would not find out until they were ready to tell her.
She does, however, find out when she sees their intimacy in an empty classroom. Jealous, Naomi uses this in favor to get back at her by kissing Annie's ex-boyfriend from Kansas at Annie's sixteenth birthday party.
She also finds out that she shares a half-brother with Naomi from a previous high school relationship between her father Harry and Naomi's mother. She and Ethan later part ways and she gets back in Naomi's good books.
In the season finale after prom, Annie is framed when Naomi's sister Jen ends up in bed with Liam. Jen had taken Annie's wrap earlier, to which Naomi finds the wrap and a half-naked Liam in her room, automatically believing Annie had slept with Liam, as she confronts her in front of the entire class. This leads to everyone turning on Annie and abusively shouting at her, resulting in Annie storming out and calling the police on Naomi, and then taking a bottle of vodka when she drives off.
In the morning Annie is seen driving with the now half empty bottle of vodka. She takes her eyes off the road and ends up running someone over and driving away out of fear. In the second season, Annie breaks away from the group and becomes somewhat of a loner due to the secret she is hiding and the resentment Naomi has for her.
At the beginning of Season 2, they are all at a beach party when she meets up with Mark, a senior. He gets her drunk and finds a way to get a cabana. Annie is not aware, however, that he had taken a naked photo of her topless. When that photo is sent throughout her school by Naomi, Annie has a resentment against Mark, but then forgives him.
She later agrees to a date with him where there is a confrontation between her and Mark. Just as Mark is about to date-rape her, Jasper swoops in to save her from him, who she had previously turned down to hang out with earlier.
She falls in love with Jasper, a drug dealer and the nephew of the man she killed. After her estranged friends confront her with news that her boyfriend is a drug dealer, she confronts him about it.
He informs her he knows that she killed his uncle, and then blackmails her so they can continue dating. Annie later decides she does not care about Jasper blackmailing her and forgets about it. He continues to threaten her with pictures of the damaged vehicles, but she informs him that if he still wants a chance to be with her, he won't go to the police.
As Annie starts to move on, Jasper watches from afar. Jasper calls Annie to tell her that if he can't be with her there is not a reason to live. Annie frantically goes to Jasper's house attempting to find him. She figures out he is at the Hollywood sign and goes to stop him.
The two have a brief encounter before Jasper jumps off the sign. Annie visits Jasper in the hospital, where she tells him that their relationship was just based on lies.
He tells her that he will always love her, and because of this, he won't tell anyone her secret that she ran over his uncle. Annie leaves the hospital smiling with relief, as she feels a huge weight has just been lifted off her shoulders and she does not need to worry about Jasper any more.
Annie's parents start having marital problems and Annie has no one to talk to because Dixon won't listen to her. She goes to Liam for advice. Annie and Liam become close, hinting at a potential relationship. Jasper shows up at school and forgives Annie. Annie says she forgives him too, but they can't be friends because of what has happened in the past. Annie becomes closer to Liam and they share their family problems.
Liam takes Annie out on his boat and she tells him about the hit and run. He encourages her to confess, they hug, and he takes her home. Unaware that Jasper was watching, Liam is attacked by Jasper by him setting fire to his boat, which he has spent a year working on. In the season finale, Annie tells her parents she needs to tell them something, hinting about the hit and run although this isn't shown.
In the third season, it is revealed that she has been sentenced to 2—3 months of house arrest, has her license suspended and is on probation until she turns She is offered an interview for an internship by her Senior Adviser, Mr. He advises her to put the accident behind her because she has already paid her dues. However, she decides she can't lie and confesses to the interviewer that she was on house arrest during the summer.
She thinks that she won't get the internship but is shocked when the interviewer calls her and offers her the spot. It is then revealed that she has a secret motive and believes that Annie is desperate enough to do it. After she confesses to the interviewer, Liam and her finally kiss but she refuses to pursue a relationship because of Naomi and they end their friendship.
She and Liam begin to date with Naomi's approval but soon break up after Liam almost gets her arrested after being caught on a boat that Liam claimed he was attending to for. She then pursues a relationship with Liam's half-brother Charlie whom she met in a coffee shop. She is not aware at the time that he is Liam's half-brother. Liam then moves into the Wilson Household to get closer to Annie. Although she does like him back, she finds out that Charlie and Liam are related after she introduces the two.
Furthermore, when Annie tells Liam that she is going to break up with Charlie and take his side, he dismisses her and tells her she was right. Liam then walks off with the girl who paid in the bachelor auction. Annie stays with Charlie but when Liam is injured and moves in with her family, Annie admits that she still has feelings for Liam and they sleep together. The next day Annie feels guilty and asks Liam to let her think. After talking to her cousin Emily about the situation, she tells Liam that she wants to be with him but he turns her down because he and Charlie talked it out.
He also tells her to stay with Charlie. Later, after Charlie discovers that something is going on between Annie and Liam, Charlie texts Annie with Liam's phone, saying, "Come see me tomorrow. Annie goes to Liam's house where they realize that it was Charlie who sent the text and finally become a couple. Yet, the drama is not over with Annie since her cousin, Emily, is causing havoc for her. Then, Annie and Liam work together to expose Emily for who she really is and she leaves town. Annie later starts to work as an assistant for Marla, a washed-up old actress who suffers from an early stage of alzheimer's disease.
Annie quickly bonds with Marla, and the two form a close friendship, which doesn't last long as Marla commits suicide, and leaves her entire estate to Annie. Annie's happiness doesn't last for long as she finds out that Liam doesn't want to go to college and live near her. Liam tells her that he wants to work on a boat for the summer to clear out his mind. Annie who first opposes to Liam's decision, later makes-up with him and tells him to come to her after he finds what he's looking for.
In season 4, when Liam comes back, he walks up to her and puts an engagement ring on the hood of her car. She says no, but Liam is persistent. He proposes again, traditionally, but she still says no. She tells him the reason she said no is because something must have happened while he was away to make him decide to do this. She later finds out that Liam has had a one-night stand with a widowed woman named Jane.
In the mean time Annie also discovers that she told a man, who turns out to be Marla's grandson, about how Annie knew about the suicide before the incident happened, which creates problems for her in the process to get the inheritance. Annie also meets an Escort named Bree, who tricks her into helping her escort a few foreign men. When Annie discovers that she can get a lot of money from being an escort, she continues on which eventually leads to her relationship with a famous business man named Patrick.
In the season 5 finale, Annie and Liam become engaged. Played by Tristan Wilds since the pilot, Dixon is the adopted son of Harry and Debbie Wilson, who holds a strong bond with his sister Annie. He is based on the part of Brandon Walsh from the main series Beverly Hills, He soon develops a romantic interest with his sister's friend Silver, and becomes her boyfriend after helping her with the school play.
They continue to grow close after spending a lot of time together. In "By Accident", he breaks up with Silver but then reconciles with her in "Help Me, Rhonda", when Silver indicates that she's in love with him. Silver loses her virginity to him on Valentine's Day after a romantic dinner in which he gives her a bracelet. After finding out that Silver got a tattoo of his name, he is uneasy and has second thoughts about her.
Their relationship continues to deteriorate as she exhibits strange and unusual behavior, which reaches a climax when she films them having sex without his knowledge and then shows the tape to an entire theater as her English project. Although Dixon breaks up with Silver after this, she continues to act out in an erratic fashion, and Dixon eventually realizes that she is suffering from bipolar disorder , a condition that his birth mother also suffered from. Dixon calms Silver down and they take her to the hospital.
Claire's School for a better semester. He then helps her re-adjust and get back to her old life. They decide to go to the prom together. Dixon is voted "prom king", and after he rigged the results, Silver is awarded the West Bev. During her speech she admits that she's not prom material, which creates distance between her and Dixon. At the after party he opens up to Ethan that although it hasn't been easy between him and Silver, he loves her.
When Dixon realizes Ethan has a crush on Silver, he confronts him about it which forces Ethan to reveal it in front of him and Silver, and it strains their friendship. In the season 2 premiere, it is revealed he and Silver are not together, but about to reconcile. However, he learns from Teddy that she had been texting Ethan in secret and they shared a kiss, causing him to tell her he's done.