Childrens fairytale picture book witch and frog collect stories

The book is about a frog who meets a young girl, and they start collecting stories in a bag so that the little girl can trade them with a fairy princess/queen/? and become a fairy. Later its revealed that the little girl is a witch and comes from a family of witches. In the ending of the book the girl finds out she cannot trade the stories in the bag to the fairy queen for a reason i cant remember (I think because she had been keeping them by getting little memorabilia/trinkets from each person she asked which was meaningless to the fairy queen/?) but she ended up becoming a fairy anyway. I dont know if the stories were classic fairy tale ones, or just stories with a fairytale-esque fantasy vibe. Im pretty sure they talked to a troll/ogre at some point. And a grandmother witch?

I read around early 2010s, maybe 2009-2012, and it looked fairly modern/recent. I think the art style was graphic/illustrated? The cover of the book may have been yellow (but not sure). It was definitely aimed at the younger subsection of children so not very textheavy.