Well its ok to be a beginner, we all started somewhere, welcome to the sport!! At this point, i wouldnt worry about swinging up too much. In fact, you should just be getting used to what it feels like to run with a pole and plant it. Hold about 8 inches higher than you can grab the pole just standing up, and take about 6 steps into the box, jump, and keep both arms straight as you glide into the pit. Raise your grip 3 inches as you feel comfortable. The faster you run, and the taller you are when you jump, the easier it will be to make it into the pit. Work on that for a while before you try to swing.
P.S. 5 feet for a 7th grade girl is just fine!!
