Constance dobler

Constance Dobler is the daughter of Mr. and Mrs. Dobler, the older sister of Lloyd Dobler, the ex-girlfriend of the unseen Tim, and the mother of Jason Dobler.

She takes Lloyd in due to the fact that she needs a babysitter for Jacob and their parents are in Germany during the film.

Her boyfriend left her probably after he realized that he wouldn't have been a good dad. We never see/meet Tim.