Debbie first appeared in the Season 2 episode, The American Dad After School Special. In the episode Steve is trying to escape from gym through the air vents and finds Debbie's hideout. The two develop feelings for each other when Steve finds her personality fascinating.
Though Steve had feelings for her, he was nervous to ask her out so Stan fit a collar on Steve that would kill him in 24 hours if he didn't ask out Debbie--however Stan accidentally set it for 24 minutes. Steve reaches Debbie's house just in time and asks her on a date. She goes to the Smith house but when Stan sees how overweight Debbie is, he refuses to let Steve go out with her, though Steve defies his father. Francine, Hayley and Klaus also come to Debbie's defense by pointing out that Stan has no right to judge people for being overweight, as he's arguably just as fat as Debbie is (though his suit hides it). After Stan realizes that they're right, he become extremely self-conscious about his appearance and goes on a crazy exercise program and gains an unhealthy obsession with his weight, even getting a verbally abusive personal trainer named Zack (later shown to be just part of Stan's imagination). Stan eventually becomes anorexic, which develops to the point of Stan seeing himself as getting fatter despite becoming virtually nothing but skin and bones. After the family makes him join an anorexia support group (during which he befriends a girl named Veronica who teaches Stan how to fake eat food into fooling his family that he's getting better), Steve comes to believe that Debbie was the source of his dad's problem and decides to break up with her, though it breaks his heart.
Stan sets Steve up on a date with Veronica, and the three end up on the same restaurant as Roger (the alien who lives with the Smith family) and Debbie--Roger invited Debbie to the restaurant as well due to being in love with her too. When Francine and Hayley confront Stan after discovering that he wasn't actually eating the food he was given, Steve gets mad that he essentially broke up with Debbie for nothing and tells Stan he loved for Debbie who she was and didn't care whether or not she was fat. Debbie overhears this, and she and Steve get back together. After seeing how happy they are, Stan accepts their relationship and overcomes his anorexia.
In Iced Iced Babies, Debbie ultimately becomes Franicine's rival over her son. After framing Steve for drug possesion getting him suspended, Steve "breaks up" with his mother. This leads to Francine wanting another child setting up the rest of the episode. At the end of the episode, Debbie dumps Steve for reasons unknown, much to Francine's delight.
She appears in Escape from Pearl Bailey and gets back together with Steve, which makes his friends jealous. After seeing how corrupt Lisa Silver is, Steve convinces Debbie to run against her for class president. Steve shows his support, neglecting his friends. Though Debbie was winning, a slam page was posted costing Debbie the election. It's believed Lisa Silver and her friends were behind it so Steve plots revenge, even though Debbie wanted to let it go. After Steve gets his revenge, Debbie gets enraged that Steve would stoop to Lisa Silver's level and dumps him again. Steve then learns that his friends were the ones that posted the slam page due to their jealousy. Meanwhile, Lisa Silver rounds up the school to beat up Steve and even gets support from Principal Lewis as Lisa's friend, Janet, is revealed to be his daughter. After making it to the Gothic area of the school, Debbie defends Steve and his friends, finally realizing why Steve did what he did. The Goths hold the rest of the school back but they get past and ultimately beat up Steve and his friends.
Bar Mitzvah Hustle is currently her last major role. In this episode, Debbie dumps Steve for Etan, as Etan was seemingly more mature. In retaliation, Steve hatches a plan to steal Etan's Bar Mitzvah gifts which goes off well. Etan accuses Steve and throws a tantrum which shows off his immaturity, making Debbie see how immature Etan was. Snot, Steve's friend, messes up the plan and gets himself accused. With Debbie as his girlfriend again, Steve tries his best to ignore Snot's trouble. When Steve learns Snot would be kicked out of Temple, Steve finally comes clean about the plan. Debbie breaks up with him yet again and Steve nearly loses Snot as a friend too. Steve sells his toys and funds a Star-Trek themed Bar Mitzvah for Snot, renewing their friendship.
- Debbie likes to shoot the eyes out of squirrels which impresses Stan, earning his respect.
- Steve claims she smells like a glue stick.
- She has brief appearances in 100 A.D. and Phantom of the Telethon.