Avigail and her Imagination

Avigail our 4 year old, has an incredible imagination. I have troubles keeping up. She will pretend she is the girl in any and every movie (examples: Ariel, Susan or Lucy in Narnia, Fern in Charlotte's Web, Princess anything, etc...). She will interchange between characters quite frequently. I will be going through the routine of the day, asking her (Avigail) to come brush her teeth and she respond by saying, "no mom I'm Fern" and then proceed to tell me she needs to take care of Wilbur before she brushes her teeth. Once "Fern" brushes her teeth, then when we brush her hair she will be somebody different and low and below so am I. Now I am Susan from Narnia and she is Lucy and we need to find Aslan. I am not an imaginative person so I have to stay on my toes.