She is portrayed by Heather Stephens.
Jill is a shy librarian by day and a sexy dominatrix by night. She lives in a house with a picket fence with her grandmother, a retired librarian who is also a dominatrix. Her BDSM dungeon is disguised as a little girl's bedroom filled with toys and stuffed animals.
Jill makes her first appearance in the movie, where Michael Delaney, the film's protagonist, has been told by Natalie that she's planning to marry Kyle Brenner and decides to move on from Natalie by seducing the first woman that he meets; unfortunately, the first woman turns out to be overweight and unattractive. Michael then sets his sights on Jill, a seemingly shy librarian. He takes a copy of The Scarlet Letter from a cart of overdue books and gives it to her, pretending to be returning it. Later, Jill and Michael walk home from their date at a sushi restaurant, and they stop by Jill's house. Jill invites Michael inside; Michael initially declines, but changes his mind. Michael meets Jill's grandmother.
Michael and Jill then go upstairs to her bedroom to make love. Michael picks Jill up and takes her to her bed. Jill then turns the tables on Michael by handcuffing him to the bed, then presses a button that automatically seals all the windows in the room. She then reveals her true colors as a sexy dominatrix, going to her toy chest and pulling out a pair of purple latex boots which she puts them on.
Jill then presses another button that reveals a hidden pulley, which she turns, lifting Michael up into the air. She then goes back to the bed, pushes it aside, and pulls back the curtains to reveal BDSM equipment. Jill brags to Michael in a sexy voice about she knows about boys who don't respect library books. She goes through her bdsm equipment and chooses a large paddle with the letter "A" on it before telling Michael that he will receive a spanking each time that his library book is overdue. After painfully spanking Michael, Jill, unsatisfied, states that something is missing. Her grandmother then walks into the room wearing leather clothes and cracking a whip, much to Michael's fright.
Jill makes her second appearance at the end of the movie, where Kyle is in her dungeon but, unlike Michael, is happy to indulge in his BDSM session with Jill and her grandmother.