I know you wrote this several years ago...so hoping maybe you are an old pro by know and you got some answers and advice...my little champ, now 23 months old does not even register on the growth charts. He has a hand tremor as well, very noticable. He had been tested for celiac as well, normal. He was on elecare formula for his first year, and that was all he could eat, no other foods. now he eats any and everything. he loves veggies, milk, water, meat, everything. He does have delayed gastric emptying...but he is a tiny fellow, and has those hand tremors still...did you figure out what was causing it in your peanut? did she ever catch up?