I’m trying to find a book (teen SciFI I guess) I read probably in 1998ish. There was a girl living on a alien planet. Someone looked after her but not a parent. I think she had to wear a suit all the time. She had a pet dog type thing which dies (it gets attacked by another alien animal). She finds out she is a scarlet alien creature and she didn’t know! Any ideas? I think there is a human boy there who she makes friends with. She thinks she is a human and that she has to wear the suit to breathe but it is to hide her true identity.