First and foremost, you're 13 and she is in her mid to uper 20's. ?So your comparing apples to oranges. ?Do not get frustrated, as bretman said, with proper mechanics and fundamentals, those extra base hit will come.
One thing that I think is under utilized is overloading and underloading. ?They key to hitting with power besides strength, is bat speed. ?Not enough players are working to create bat speed. ?A couple times a week you need to add some weight to your bat with a weighted tuff sleeve, or just use a heavier bat. ?Take 30-40 swings, off a tee or soft toss with the weighted bat, focusing on proper mechanics, then remove the weight or use a lighter bat for 30-40 more swings, concentrating on getting the bat to the ball as quickly as possible. ?This should increase your batspeed over time, which will increase you power. ?GOOD LUCK!!!