Jack (Not Jackie) by Erica Silverman
Plot Summary: In this heartwarming picture book, a big sister realizes that her little sister, Jackie, doesn't like dresses or fairies-she likes ties and bugs! Will she and her family be able to accept that Jackie identifies more as "Jack"? Susan thinks her little sister Jackie has the best giggle! She can't wait for Jackie to get older so they can do all sorts of things like play forest fairies and be explorers together. But as Jackie grows, she doesn't want to play those games. She wants to play with mud and be a super bug! Jackie also doesn't like dresses or her long hair, and she would rather be called Jack.
Youtube link: https://www.youtube.com/watch?v=F0XfwBcpOf0
This book is a nice one about a sister who is sad about her little sister’s transition, until she realizes that her trans brother is still the same person he always was. The author’s note was very nice as well.