a tv movie A babysitter watching some kids is held hostage by the oldest son of the family. At the end the father and hidfamily kidnap her?
I know that the babysitter is between late teens to early twenties. She was watching two kids (a boy and a girl) when the oldest son (around her age) shows up.
It's not Mother's Boys. It was definitely a newer type film. The main lead girl is a blonde, not Jamie Lee Curtis.