Visible crew/equipment: When Grace thanks her father for "The Scream" punching bag, just as Maxwell says, "Oh, I'm glad you like it, sweetheart," and a moment later as he says, "There's my big girl," in both of these shots the boom mic dips down into view at the top of the screen. (00:10:35)
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.