That 2 thing didn't work for me at all. I was told I was going to be 4'8" at full height-imagine how I felt when I was 12 and 4'8"!!!
I don't know if this alarmed newfsmith or not?
My 5' tall sister was supposed to be 5'6".
Anyway, I decided to grow another foot, making me the tallest chick (and nearly the tallest overall) in our family.
I recently read something about children tending to be between the mom and dad's height. I don't know how reliable that is, either.

I agree though, growth spurts are individual. Just puttin' the idea in your head knowing it happens to the best of us.