Need help

Hi I'm Nicola. My youngest sister is Autistic and me and my mum need help as she is struggling with some parts of her Autism and we're not sure how to help her best. We tried the gp but they don't really understand her and haven't been able to help yet but it's getting quite bad now and I'm hoping that people here will understand some of Becky's problems. We understand that she's got difficulty with some things but we don't know how to help. Becky is struggling in many ways, some are only in small ways but others are quite bad and serious. I'll start with the big problems. Becky hardly eats a thing. She's very thin and underweight but she just won't eat. I've tried explaining the importance of eating and mum tries to make eating as fun as possible but nothings worked. Any tips or help with this would be greatly appreciated. She struggles to drink as well. Don't know how to help her. Another problem is sleeping. Becky only gets about 3 hours sleep, and then she spends the rest of the night awake and she has to be watched otherwise she could just herself. One night mum spends it awake with her and the next I do. It's so hard, we're really tired but we can't get Becky to go to sleep. She never seems to be tired. Another problem is with going out. Becky is terrified of going out and when she does she'll usually have a meltdown. We don't know how to calm her down or make it easier for her. She has this little comfort bear which she carries with her, but she won't let him out the house. And then there's this thing with coordination. She walks into things a lot and falls over. She's hurt herself a lot doing this and we don't know how to help her with this.

Sorry for the long text but we really need help for Becky. I hope you can help us with some of this. Thanks in advance.