- "I'm not a little girl anymore, understand? So from now on, butt out!"
- —J.B. Slater to A.C. Slater
A.C Slater's little sister and she dated Zack Morris briefly
Grew up as a military Brat, traveling the world with her dad & brother. Spent her 10th grade at boarding school, then went to Europe for the summer.
J.B. shows up suddenly to visit A.C. and Zack develops a crush on her. This makes A.C. angry as he knows how big of a womanizer Zack is, and forbids them from seeing each other. Once J.B. learns of this, she confronts Slater angrily and tells him to butt out of her love life. Slater eventually realizes that it is wrong to control his sister's life and gives his blessing, but still privately confronts Zack that he expects nothing but gentlemanly behavior when with her, or "you must treat her right".
- J.B. & her brother A.C. Slater, have initials they use for first names.