I read this book somewhere between upper elementary and early high school, so between about 1991 and about 1997, but it seemed older even then. I remember only vague bits, but it’s stuck with me. A girl is seriously injured in an accident and to prevent her from living as a quadriplegic or possibly dying her brain is transplanted into the body of either a chimpanzee or gorilla. She understands language and remembers being human but must learn to communicate through sign language and live within an ape body. Much follows about socialization and coming of age as an ape and both comedy and tragedy. In the end she chooses other apes over her human family, and at a later date they (scientists? Her human family?) observe she has taught sign language to her offspring and some fellow apes. Does anyone have any clue what this book might be or why it was suggested reading?

Thanks!