When I was a child, this would have been sometime between 1990-1995, I borrowed a fiction chapter book twice from my local library that I cannot remember the title of. At the time, the book was old, but I was a kid so it may not have been THAT old. I think it may have been written sometime around the 1950s-70s. It was a story about a boy who takes care of a squirrel. I think that there was a red squirrel on the cover, and the title of the book may have been the name of the squirrel but I’m not certain. I think the book had a bittersweet ending with the squirrel going back to live in the wild. I’ve not been able to find it on a google search so perhaps you can help!