My sister Alexandra gave Fiona this picture book about what cats do at night when we are sleeping.
So Doug is reading this book to her before bed. One scene shows the cats working at a factory boxing up the mice. Fiona asks Doug, "Why are the cats boxing up the mice?" Doug says, "Well, I think they mean to eat them."
Fiona is not at all happy with this answer.
Now she wears her blue apron around her neck like a cape (she actually has a cape, but it's a hooded cape) and says she is Super Mouse, saving the mice from the bad cats.