There are seven children in the Brown family, and they are all very clever and exceedingly naughty. The 16th nanny has just quit because she thought she saw the six older children eating the baby. The nanny agency refuses to send over another candidate. Mr. Brown (Colin Firth) does not know what to do. And rich Aunt Adelaide (Angela Lansbury) says that if he doesn’t get married by the end of the month, she will stop sending the money they need to pay for their house.

Enter Nanny McPhee (Emma Thompson). She has two huge warts, a nose like a potato, and a snagletooth. She also has a big, gnarled staff, and when she hits the ground with it, surprising things happen. She tells the children that when she is needed but not wanted, she will stay, but when she is wanted but not needed, she will go.

Thompson, who also wrote the screenplay, clearly enjoys her outlandish get-up and her crisp but understated and dryly humorous delivery is perfectly suited to the part of the un-ruffleable nanny. Firth’s addled but affectionate father and Kelly Macdonald as a sympathetic housemaid add some substance and sweetness. Thomas Sangster (Love Actually with Thompson and Firth) as the oldest of the Brown children, has a light comic touch.

The movie is a little too self-consciously charming, set in a village so twee it would not be out of place in a Christmas display, with owlish children making adorably precocious quips. And some of the humor seems forced or even creepy, as when we see Mr. Brown working in a mortuary. But it is highly entertaining to see the children misbehave — and to see them get their comeuppance, and the happy ending, if unsurprising, is welcome and satisfying.

Parents should know that there is some gruesome humor and comic peril (no one hurt). There is a comic situation involving some accidental but graphic groping and a woman who takes this as evidence of her sexual attractiveness and a brief crude joke with the implication of incest. Some audience members may be disturbed by the (offscreen) death of the children’s mother or the potential wicked stepmother or loss of the family’s home. Mr. Brown works in a mortuary and the film includes shots of dead bodies.

Families who see this movie should talk about why the children were so naughty. What was the most important thing they learned from Nanny McPhee? What do you think about her rules? Why do her looks change? If you were nanny to the Brown children, what would you do? What does it mean to be needed but not wanted or wanted but not needed?

Families who enjoy this movie will also enjoy Mary Poppins, the Mrs. Piggle-Wiggle books, and The Storyteller, the classic story of a man who finds a very clever way to quiet some annoying children. Like the author of the books that inspired this movie, he knows that kids love stories about naughty children.