My DD is 4 and was labled ftt, however after all the tests came back norm/neg we (parents and ped) decided she was not. The specialists however wanted to keep testing for ridiculous things because they wouldn't accept that she could very well just be small and healthy. So we cancelled all our follow ups...with our peds permission.
She fell off the charts around 4 months and never really got back on them..stayed in the neg 5th percentile till she was 2 I think? At which point she got on the chart for weight, maybe 5th percentile and fell off for height
At this point she is and always was healthy just small. She turned 4 in March and weighed 32lbs and maybe 34 in? Small very small. She was 12lbs when she started walking at 9m and around 13lbs at a year! Our ped was awesome thru the whole thing...as long as she was following her own growth curve he was fine with it.
I will come back and give you more details later when I have a bit more time.