- "Oh my God, I hit on your mother!"
- —Zack to Jessie after finding out she is her new stepmom[src]
Not much is known about her early life except that she worked at a gym at Palm Springs where she became the personal instructor to Jessie's father David, fell in love with him and accepted his marriage proposal.
Leslie is kind and thoughtful, who loved Jessie's father deeply and played along when Zack made a fool of himself to impress her. She is also very forgiving after Jessie became jealous and rejected her attempts to befriend her.
Leslie and David invited his daughter Jessie, Zack, Slater, Screech, Kelly and Lisa to a vacation at the Palm Springs Hotel and to be special guests at their wedding
When Leslie first met Jessie, it took off to a bad start. Jessie became jealous of how fit and beautiful she was and became horrified when it turned out that she was her father's fiancée.
Although she became good friends with the others, Jessie resented her for marrying her father who was much older than her, thinking she would take advantage and make him forget about his daughter, so she tried several attempts to drive her away but all in vain.
Finally at the wedding Leslie couldn't stand it any longer. She told Jessie how unfair she was for not giving her a chance and her wedding would not be ruined.
Eventually Jessie left, but after some persuasion from Zack, she returned to the wedding and Leslie forgave Jessie for her earlier actions. She married David and Jessie became her step-daughter.