Dorothy Wheeler is a Supporting Character turned main antagonist in Valentine. Adult Dorothy is played by Jessica Capshaw (Steven Spielberg's stepdaughter), who is mostly known as Dr. Arizona Robbins in ABC medical drama series Grey's Anatomy.
Biography[]
In 1988, she lived in San Francisco and was an overweight girl. At the Valentine's Day high school of 1988, she was approached by Jeremy Melton. Like him, she did not have a date for the dance and was first seen sitting alone on the bleachers at the side of the dance floor. And when Jeremy asked her to dance with her, she agrees. So they secretly make out underneath the bleachers. Then some bullies (2 of them are presumably a younger version of Gary Taylor and Campbell Morris, although the 3rd bully is unnamed) led by Joe Tulga find him, and Dorothy, feared of being permanently humiliated, falsely accuses Jeremy of sexually attacking her and calling him a pervert, so Joe and his buddies beat Jeremy up and give him a nosebleed. They chase him around in his pants before Jeremy was sent to reform school.
In 2001, Dorothy has finally lost weight, dyed her hair blonde, and lives in a rich mansion, but she is not close with her father who prefers his mistress (Dorothy's stepmother Kim) than his daughter. Also, ever since childhood no boys want her until Campbell walked in her doorstep, unaware that is in fact a conman, wanting his hands on her family's fortune.
At Shelley's funeral, she, Paige, Kate, and Lily are questioned because they haven't seen her since she moved from San Francisco, to Los Angeles.
When the girls finally realize the threatening Valentine messages signed "J.M." came from Jeremy Melton, Dorothy, in guilt, admits to Paige and Kate that she lied about Jeremy sexually attacking her and feels responsible for ruining his life.

Dorothy in 1988, falsely saying Jeremy Melton sexually attacked her and calling him a pervert.
Death[]
Dorothy gets into an argument with Kate as to who is the Cherub killer, both claiming Kate's boyfriend Adam Carr and Campbell respectively. Dorothy eventually goes off on a rant about how the other four girls were always smarter and prettier and more popular than her in junior high, and she was always “the fat one.” She then angrily darts off.
While suspecting Adam being the killer, Kate gets confronted by the Cherub who knocks both of them down the stairs, before the Cherub Killer is shot to death by Adam and unmasked to reveal dead Dorothy. But as the movie ends, Adam's nose bleeds revealing to the audience he is Jeremy Melton and the actual killer all along, framing dead Dorothy for the murders as payback for falsely accusing him for sexually attacking her.

Dorothy shot to death.