Continuity mistake: Just before Fran opens the door for her date, her handbag switches hands between shots when she says, "It's cuter on me."
Continuity mistake: When Fran and Val are in the sports bar in the beginning, the popcorn in their hair changes between shots. This is especially obvious on Val.
Continuity mistake: In the dining room during breakfast, while Fran is talking, Niles starts to turn away from the window towards Fran with a teapot in his hands. When the shot changes he is facing the window again and turns around with the teapot a second time.
Answer: Mr. Sheffield needed someone to manage the kids, not necessarily babysit them. Brighton was a Bart Simpson type, Maggie was shy and awkward and Gracie had personality issues.