S.W.
Your niece is not developing according to averages. She has seen a specialist and is getting PT. There may or may not be anything more to be "done" at this stage. I would suggest broaching this subject very carefully and politely if at all with the parents. I have a brother with three boys who all have had developmental delays due to premature birth. Our family was concerned that the parents weren't addressing the issues, but later found out that they had gotten diagnosis, treatments, and special services that they had not shared with us. They didn't want their kids to be a set of diagnosis and labels to our family, but just boys. In the end, this girl's parents are in charge of her care.