I agree with the idea to test for gluten intolerance; I'd even go so far as having a Naturopathic Doctor test for all food allergies/intolerances, because different food intolerances and allergies have lots of different symptoms.
My daughter had a lot of foot and lower leg pains (still has, actually; she's 10 in April). We know she is going to be very tall, so are expecting that she will have a lot of growth spurts. She did get tested after my husband and I discovered we have casein allergy and soy and gluten intolerance; she has a mild glulten intolerance. If she stays away from eating gluten, her leg pains stay away as well.
You could also try giving your daughter bananas more often--she might have a potassium imbalance, which will make your feet and legs hurt with cramps/pain. Also, when my daughter starts complaining about her feet and ankles hurting we've come to learn to check her shoes. We've found that either they're too small or the support cushioning is out; if we buy her a new pair, the pain goes away.
But I definitely would check for food allergies and intolerances. When she's in her middle age years and knock on wood, not sick, she'll thank you for finding out what foods don't like her and for staying away from them. I didn't discover my food problems until in my 40s; not an easy task, getting my health back in order.