I know exactly what you are going through. I have a niece who is extremely small for her age. She is 10 years old, but her bone age is that of a 6 year old. BUT most people guess her to be 4 or 5. She has a 6 year old brother and some people think that they are twins. She has seen an endoconolist (sorry for the misspelling). She's been testing 3 times for growth hormone deficiency 3 times. First 2 times, it was apparent that there is a deficiency. The third time, there was no deficiency. This 3rd time was right before Christmas. The doctor then said that her bones appear to be small and fragile, and that she should see a bone specialist. She might have bone disease. My sister and brother-in-law are divorce, and they too have different opinions on the matter. He wants my niece to be put on hormones, my sister does not want her to be. But my sister did learn that they now can do the shots in the same way that diabetics test their blood - with a machine like that so it's not like a shot.
Anyway, my niece has had problems from day one. She had extreme relux when she was born. She literally threw up everything she ate so she had a feeding tube first in her nose, then it changed to a g-tube in her tummy until she was like 5. She now eats like a champ, though. Always hungry! But she doesn't gain weight (btw, she only weighs 40 some pounds - and she is 10!) My sister and ex-brother-in-law are really thin people - very petite. My poor niece has never even made it on the percintile charts - always below zero percent.
They are now just waiting to get her into to see the bone doctor. I don't have any real advice for you. I just wanted to let you know that I feel your pain and frustration. ( I love my niece like she is my own daughter). I hope that you get some answers soon!
SAHM of 1