Hi Hilly,
Motherhood exhaustion is the pitts and at such a late stage of the game. In infancy you expect it. It must be hellish for your daughter. She must be exhausted all the time and her grades will supper as well as the quality of her life if not treated.
I'm wondering if you may need to have sleep studies done on her if she in fact is sleep walking every night. She may not be getting qulity REM rest.
Has anything changed in her life? New location, school, difficulties at school, with friends...or upsetting to her?
Is she over scheduled with sports, and activities?
All of these things can be remedied.
Talk with her and see if anyting is bothering her.
Have your pediatrician in on the situation and then a follow up with a sleep specialist is in order.
Blessings!
Please get back to me and let me know how it goes.
I care.
Justine