I'd look at the rates of gigantism, because being nearly 7 feet tall as a woman is generally an indicator of gigantism, IIRC.
I'd be surprised if it was higher than 0.0001%, which, if I'm eyeballing my math correctly, would be about 3500 women, assuming a back of the napkin 50-50 population split.
In my typical majority White American Public Highschool of between 2000 and 3000 students, I personally knew about 4 teen girls who seemed to be done growing who were less than 5 feet tall, and saw many more.
Amongst White Americans, they're outside of the norm, but not rare enough to be worth commenting on, whereas any woman over 6 feet tall draws some level of attention for being unusual. It would certainly figure into teasing and bullying, though, unless it was in an area where the female average was around 5'2" or lower.
IIRC, they're about as uncommon amongst Black Americans, maybe a little less so. I think they might be a little more common amongst certain subsets of the Latino population.