First of all, make sure she’s on the right dose for her body size.

If that’s not a problem, look at what she’s eating. Try to limit or eliminate processed foods, white breads & pastas, dairy products, lunch meats, fried foods, hydrogenated oils, high fructose corn syrups, etc... Offer her more whole foods, fruits, vegetables, whole grains, lean meats & dairy products if you choose. Keep a bowl of cut up fruits or veggies on the counter and let her snack on those instead of junk food. You can make delicious fruit smoothies with frozen fruit, milk, and even flaxseed to give her a little extra healthy fat. I agree with the 6 small meals instead of 3 large ones.
hth...good luck