Hi there and thanks so much for posting this question. Feel free to post it in the Neurology forum as well.
At that age it is not unusual that people who experience more episodes of "limbs falling asleep"
In most cases, you feel this familiar sensation after you've been putting pressure on part of your body -When you apply this pressure for a prolonged period of time, you actually cut off communication from your brain to parts of your body.
Ask her to maybe change the way she sleeps in the case it can be a pressure to a part of her body. On a side note you would like to check that her levels of hydrations are appropriate and that follows an appropriate exercise program and healthy nutrition plan.
Hope this helps!
It may be a case of neurological problem, but normally this kind of problem doesn't occur so early. Suggest your daughter to try some other sleeping posture & also at the same time she can start doing yoga, it is very good for overall neurological problem & sleeping disorder problem, For better understanding of her problem, keep an eye on her & if things doesn't change take help from a Good Physician.