What is the lullaby they are talking about in Nanny McPhee and where can you find it?

In "Nanny McPhee," the lullaby referred to is "The Lullaby of the Bough." It is a soothing song sung to calm the children and is integral to the film's themes of family and nurturing. You can find it featured in the movie's soundtrack, which is available for purchase on various music platforms or streaming services.