Average about 10-15 mph
For a 15 year old boy of average height (5'9") 150 pounds For a 15 year old girl of average height (5'4.5") 121 pounds
The average weight for a male 15-year old is roughly 125-140 pounds. The average height for a male 15-year old is 5'7.
My daughter ran a 5.7 40. She'll be 15 in October.
In the Bahamas 15 year old girls run about 12.40 boys run about 12.20
3
15 mph sprinting full speed is average for a 10 year old. Also, a 10 year old to run a mile in 9 min and 45 sec running as fast as they can.
There is no average shoe size for a 15 year old girl. Shoe size can vary and it depends on height.
I am 15 and i can sprint up to 34.8 mph other juniors on the team sprint up to 28-29 mph that i know of.
5'5-6'0
Think of it like this the average height of a 17 year old girl is 5 foot 4 inches so you are growing at a good speed
125