I'm almost 5'3" and I weigh 115lbs and I thought that was alot and I want to lose weight! But if I saw you too, I'd be very worried. I don't see many people with ED's, but as a stranger and not knowing you, or what you look like I'd say you're very underweight. My boyfriend calls me chubster. But he says he likes my baby fat? (Don't know how!) You aren't fat though, and when my BF calls me fat, he says he's only kidding. But hang in there. I don't know what your relationship is with your sister is either, but hang in there and be strong!