When you need me but do not want me, then I must stay. When you want me but no longer need me, then I have to go.
Nanny McPhee is a governess with magic powers, we could define her a horrible looking Mary Poppins! She always arrives not wanted, but called to manage the situation. Once her task is completed, she has to go, even if she is now wanted.
In both episodes, Nanny McPhee (2005) and Nanny McPhee and the Big Bang (2010), she has to reform naughty children: she uses a magic stick; at first, children can’t stand her, then they love her but… she has to leave because she has completed her mission.
Emma is unrecognizable because of the cinematic makeup and only at the end of the movie , for few seconds, we can see her pretty face again.