I have a DD but similar experience; since birth had a height percentile in high 80s to 90s which fell when she barely grew in middle school. Hand X-ray showed bone age is 3 years behind biological age. From 14-15, the growth spurt started and she was back on track with probably several more inches left to grow. Seems to be very late bloomer but we also watched closely and did some bloodwork around age 14 to confirm nothing else was going on as her eating habits and intake are not great. Looks like all will be fine but we’ve been worried, especially as many girls are finished growing, or close to it, by this age, and she hadn’t even started yet.