Now if she's not the cutest thing I've ever seen!!!! Bless her little heart. She sounds like a fighter, just like my Evan. He had a rough start with Hypoglycemia, I almost lost him 3 times. He lost all his hair from only eathing baby food that was syringe feed for a month straight. I thought he would stay tiny. I couldn't possibly place him with anyone else so I kept him. Anyway, I would suggest you have a full blood panel done on her. They draw blood (no fasting needed) and test her for a lot of stuff including Liver Shunt ( won't give exact readings but indicate whether her levels are on track or off track). I agree about the vacc comment.
Don't assume anything as far as weight goes. Even at 17 wks she can do a 180. Here is Evan at 13wks losing hair and all, and then here is Evan now! Love is the best medicine!!!