Valerie Birkhead is Sabrina Spellman and Harvey Kinkle's mortal best friend at Westbridge High School. She is also despised by headstrong cheerleader Libby, who rivals both her and Sabrina for much of the show. Valerie remains Sabrina's best friend until she moves to Anchorage, Alaska in 1999.

She is a shy and often awkward girl who looks up to Sabrina despite being quite bright herself, but is also known to be friends with Libby. Valerie often expresses her wish to be in the "cool crowd" even trying her hand, and winning a spot on the second string cheerleading squad. At the start of Season 4, she moved to Alaska with her family. She had agreed to move in with Sabrina to attend their senior year together, but then she decided to stay in Alaska instead.