There is a window of time that the GH would help her to grow in inches and that window closes at about 16 for girls, sometimes earlier depending on when they begin menstruation. I think they stop growing 2 years after menstruation begins.
Not always. I have that teeshirt.
One thing to note -- again, not so much for you, Reg5poppy, but for others who might be following -- when eldest was diagnosed as having "constitutional short stature" at age 2 or 3, our very wise pediatrician asked me and DH a lot of questions about our own individual growth patterns. Both of us grew late, and although I started menstruating just a year or so behind what was usual, I did not reach my full adult height until I was in college. My husband also picked up significant height late in high school. Based on this, our pediatrician advised us to watch but not to worry. The interesting thing about bell curves is that they have tails -- and when two people in the tails create a gene salad, well, you have to figure that landing in the middle of a distribution is significantly less likely.
When I look at my three children, the oldest looks most like his parents' pattern in terms of height. I'm guessing he may end up pretty close to his dad, if not passing him up, but he's still three inches away at 18. My daughter reminds me of myself; she has an image of herself as the shortest kid in the class, but that's not remotely realistic anymore, and she has been growing very steadily for the past two years with no signs of stopping. I am guessing she'll end up within an inch of me at around 5'5", though she was usually below the 5th percentile on growth charts. Youngest is still pretty far away from puberty, I think, but he is closer to the conventional charts and patterns than either of his sibs, so I expect him to start getting hungry and sleeping a lot more this summer.