^ No one knows for certain, there seem to be a lot of factors to growth that doctors still don't understand.
It's not uncommon for gymnast girls, even ones who get their periods at a regular age, to grow an inch or two into adulthood, I've seen it personally happen myself.
Also, males frequently think they stopped growing at 14 because that's when they received their last 4+ inch growth spurt, but it's just not true. You only feel like you stop growing because it's the last very noticeable growth, but I would estimate that on average they still grow another 2 or 3 inches until they reach adulthood.