Look My Niece Is Really Sick Shes Only 9 Years

look my niece is really sick shes only 9 years old weighs 28 pounds shes tiny and lupus runs in her family her hands (fingers) swollen as well as her feet. She can barley walk and hold things, she said she is in a lot of pain and is not feeling well. she is now in childrens hospital shes already seen 8 different doctors and they cant seem to figure out what is going on please I need some help. To get an idea of what the doctors should be looking for. what to get my sister prepared for please help me.