What Causes High Rate Of Growth In A 7 Year Old?

My daughter is 7.5 years and 4 feet 6 inches tall, and weighs 64.5 lbs. I am 5 10.5 while her father is 6 1 . Growing up I was constantly told how tall I was- instead of embracing it, I became self conscious about it. My daughter gets the same comments constantly. I am hoping it is not affecting her negatively. People think she is years older than she is and tell her so. We have taken her to an endocrinologist who has ordered bone X-rays each 6 months for the past 2 years. He has not wanted to do blood work, but wants her to continue to come back every 6 months. Her bone age is about a year and a half advanced according to him. He predicts she will begin puberty at 11 or 12. She is growing nearly 3 inches a year incidentally. He says though this is in the high side, it is within the normal range and he thinks her rate of growth will continue. He also says his guess is she will be between 5 8 to 5 11 tall, but she appears so tall compared to her peers along with having a high rate of growth that this range seems low. Can endocrinologists accurately predict female final height from age of 7 years old? Why does he want to continue to see her if he thinks her growth is normal?