Bücher der Reihe Penelope Fritter - Super-sitter S.

This is the story of Penelope Fritter.Penelope Fritter is invisible. Not in the cool, super-power way. She's invisible in the worst possible way -- the symbolic way. This means people can see her. They just don't notice her. That is until she stumbles upon a very mysterious yet tasty smoothie, and everything changes in the best possible way.