- “Just once I'd like to be in the cool crowd. Oh, I know that makes me sound really shallow, I hate that about myself! Just go on without me, I'm dragging you down.”
- ―Valerie to Sabrina Spellman
Valerie Birkhead is Sabrina's best friend in Seasons 2 and 3. Valerie is a shy and awkward girl with low self-esteem. Through Sabrina's help, Valerie often learns to believe in herself more and to stop trying to fit in with the "cool crowd."
Valerie is the new girl at Westbridge High and meets Sabrina when she helps her find her locker and from there, they become friends. We learn that she is moving to Westbridge, from Minnesota, and that her family has a tendency to move around a lot. Sabrina, tied down by her other responsibilities, passes on her role as editor of the high school newspaper to a reluctant Valerie.
Sabrina, who has transformed herself into a boy, is upset when she learns that Harvey has asked Val on a date. Fortunately, she discovers that Harvey only wanted to talk to Valerie about his relationship with her. On Friday the 13th, Sabrina is able to tell Valerie and Harvey that she's a witch, knowing that they will forget it all by midnight. Valerie is very understanding of Sabrina's secret and enjoys a day of casting spells with her and Harvey. For her last spell of the day, Sabrina causes Val's wish to come true and conjures up Drew Carey for her to dance with.
When Valerie expresses a desire to join the cheer leading squad, Sabrina tries to talk her out of it. Because of her mistrust of Libby and the other cheerleaders, she uses a magic penny to go into Valerie's mind and plant evil thoughts toward the cheerleaders and Val becoming one of them if she joins the team, causing her to quit. Sabrina realizes that not letting Valerie do what she wants to do is wrong and auditions with her and while Valerie is accepted onto the team, Sabrina isn't. Valerie is a back-up cheerleader, but doesn't turn into a mean girl like Libby.
Through the combination of a spell Sabrina cast and a wish made by her parents, Valerie becomes more and more like Sabrina. First wearing the exact same outfit as her everyday and taking on some her personality quirks, then dying her hair blonde, and finally developing magical powers. With the help of her aunts' advice, Sabrina manages to reverse the magic and make Valerie's family believe that she was simply having a delusional moment. Just when Valerie begins crushing on Gordie, Salem possesses his body, causing him to become more charming, even going so far as to make out with Val in the hallway. Unfortunately, Valerie is turned off by 'this side of Gordie,' when Salem teams up with Mr. Kraft and Libby in a quest for power. After Salem is expelled from Gordie's body, he and Valerie agree to go to the dance together. It is unknown if anything comes of their relationship.
When Valerie's family decides to move to Anchorage, Alaska, they allow her to finish her senior year of high school by moving in with Sabrina and her aunts. However, Valerie doesn't want to leave her family and decides to go with them anyway which greatly upsets Sabrina as she was looking forward to her moving in with her and the aunts. She tries to remain in contact with Valerie, via e-mail, though we learn that Valerie makes a lot of new friends in Anchorage and becomes quite distracted.
- Lindsay Sloane also plays the role of Fin in the second of the two TV movies: "Sabrina Down Under."
- Valerie is the first friend of Sabrina's who is Jewish. This would return by way of Miles Goodman.
- Valerie is allergic to watermelon, which is also her biggest secret, until she reveals it to Sabrina and Harvey.
- Valerie's father is a safety inspector and her mother is a nutritionist who serves lima bean loaf and beets. She also has a brother named Warren. Valerie's family is based on Melissa Joan Hart character's Clarissa Darlings family in Clarissa Explains it all.