Continuity mistake: As Fran, Val and Maxwell are preparing to go out on the town, Maxwell's arms are hanging at his side. When the shot changes and he says "Excuse me", his hands are suddenly in his pockets.
Continuity mistake: When Maxwell comes home from his date the the amount the closet door is open changes a couple of times.
Continuity mistake: When Fran is talking to Brighton in his room, Brighton puts his baseball glove on his bed near the edge. Later it is seen in the middle, then when he goes and lies on his bed it is back near the edge.
Continuity mistake: Fran puts the magazine on the chair and sits down on part of it. The next time we can see the magazine she is no longer sitting on it, and it is now facing the opposite direction.
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.