An Unexpected Family (1996)
Starring: Stockard Channing, Stephen Collins, Christine Ebersole, Jenny O'Hara
Barbara Whitney (Channing) is a Manhattan career woman who is unwillingly thrust into the role of surrogate mom when her irresponsible sister, Ruth (Ebersole), dumps her two children at Barbara's door. Along with her friend Sam (Collins), Barbara and the children slowly make a new family but, after a year, Ruth returns, demanding her children back.