Continuity mistake: When Niles is putting the flowers in the vase, there are 3 sitting on the table, he goes over to the door and when he comes back they are now facing a different direction. Niles then puts two of the flowers in the vase, he picks up the third one but puts it back on the table. The next time we see the table the flower has disappeared then reappears in the next shot.
Continuity mistake: In the opening scene Fran puts a pad of paper and a pencil on the counter. The pencil is vertical, the next shot the pencil is horizontal, the last time it is seen it is vertical again.
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.