Continuity mistake: In the kitchen, when Fran and Maxwell are tidying up, Maxwell picks up the bottle of chocolate sauce from the table. When he walks to the sink, the bottle is suddenly back on the table, and a few shots later Fran picks it up again.
Continuity mistake: While Fran and Maxwell are changing the baby in the kitchen, the jar of baby food moves from next to the baby's head to next to his feet between shots.
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.