DD has been on the 3rd for her corrected age all her life, even before she was born. And she is fully FF.
I'm pretty sure she's fallen off the scale now and her growth rate has slowed yet again. It's part of a medical condition, but neither DH or I are very big people, we're both tall. I'm 5"9 and DH is 6"2.

If your little one is healthy and happy and not 'all skin and bones' then I wouldn't worry too much about it. Unless you are concerned.