a pre-bed snack may help. nothing too sugary, something with protein. oh and maybe a cup of chamomile tea?
some relaxing music may help, play the same thing each time to develop a sleep association.
I have read that you should not look at a screen (TV, computer, etc) during the two hours prior to going to bed. I can't remember the reason why. Something kinda like not exercising before going to bed.
If she can write very well and something that is keeping her awake is anxiety provoking thoughts, keep a notebook and pen by her bed so she can write things down. I am not sure if kids have this problem, but I can't tell you how many times I lay down and remember something I need to do in the AM and then stress I won't remember. Write it down and let it go!
something that is supposed to help is develop a routine/ritual, could be anything. another one of those sleep association things.
here's a big one that I find hard to follow, always keep the same bedtime, no matter what day of the week. your body will get into a rhythm and learn to expect to fall asleep at a certain time.
haven't tried all these ideas myself, just things I've gleaned from having trouble falling asleep myself! I hope something helps.