Nanny McPhee is a sort of cross between Mary Poppins and ABC's Supernanny (or, if you prefer, Fox's Nanny 911). While the film is neither the classic that is the former nor as instructive as the latter, Nanny McPhee is a pleasant British family diversion.
Based on Christianna Brand's Nurse Matilda books, Nanny McPhee (rated PG for mild thematic elements, some rude humor, and brief language) begins, as do many episodes of Supernanny, with a household full of screaming, out-of-control children. Cedric Brown (Colin Firth) is the hapless widower father of a brood of seven-four girls, three boys-intent on running every nanny charged with their care out of the house as quickly as possible. The score stands at kids, 17, nannies, 0, when the mysterious Nanny McPhee (the great Emma Thompson, who also wrote the script) arrives on the scene.
It's clear early on that what these kids need, in addition to discipline, is their downhearted father's attention. But Nanny McPhee, complete with warts, bulbous nose, and snaggletooth, sets about using her tenure to teach the kids five lessons. "When you need me, but do not want me," she says, "then I will stay. When you want me, but do not need me, then I have to go."
That progression is cleverly realized-Nanny McPhee's features become steadily more attractive as the kids' affection for her grows-and the kids obtain some simple but valuable instruction in the process. The film's plot is moved forward by an ultimatum from a wealthy great-aunt (Angela Lansbury), which would require Cedric to marry quickly or lose the allowance that keeps his large family afloat. But the film's finale-a disastrous marriage ceremony-goes a long way in undermining earlier lessons, as it becomes clear that it's OK for kids to be beastly as long as they pick the right targets.
There may also be some salty British euphemisms that most kids won't get. Otherwise, the film is often very sweet. All of the kids do well, and Mr. Firth, love interest Kelly MacDonald, and especially Ms. Thompson give the adult roles a luster often absent from children's films.