With the popularity of Nanny 911 and Supernanny bringing matronly, British child-caretakers to the forefront of American popular culture, Nanny McPhee couldn't arrive at a better time. This Mary-Poppins-by-way-of-Lemony-Snicket film treads familiar ground, but does so in a charming and unpretentious way that is likely to fascinate children, even if it may leave adults bored at times.
Thompson (who also wrote the screenplay) plays the titular governess, who doesn't quite float down from the clouds like Mary Poppins but does appear suddenly at the home of the Brown family, led by frazzled widower Cedric (Firth) and consisting of seven unruly children who have driven off 17 previous nannies. Nanny McPhee isn't like those weak-willed women, though, and it helps that she's got magic on her side to help bring the children in line. Soon she's even got them asking for her help in fending off their nasty great-aunt (Angela Lansbury) and stopping their father from marrying a clearly unsuitable woman.
It's obvious from the first two minutes that scullery maid Evangeline (MacDonald) is the one truly meant for Cedric, and that the rambunctious children will come to love Nanny McPhee (and that, sadly, will be right when she must take her leave). Thompson and director Jones, who was also behind the similarly slight and whimsical Waking Ned Devine, give the film a nice off-kilter charm that offsets the crushingly predictable story, and an undercurrent of genial nastiness that makes the sappy morals go down a little more easily.
Rendered unrecognizable under warts, frizzy hair and a huge prosthetic nose, Thompson doesn't overcompensate by giving Nanny McPhee an over-the-top personality. Instead, she's the most grounded character in the whole film, modest about her achievements with the children and the way she brings the family together. Lansbury, Celia Imrie (as the awful potential stepmother) and Imelda Staunton (as the family's cook), all also nearly unrecognizable, get to do all of the overacting, and it works when confined to these supporting roles. The child actors, especially Thomas Sangster as the eldest, are endearing without being cloying, and Firth plays the same quiet stand-up guy as always. By the time Nanny McPhee flies off to help her next family, kids will be clamoring for her to get her own reality show, too.