If your child has been reading Harry Potter and is now in a class learning the letter H and numbers 1-10, it must be torture for her to sit through the day like that. Her brain must feel numb and it must be very frustrating.

I don't know how much a person can stand that...

It is great that you are doing what you can to help your DD. Keep at it. Don't give up. Come back here to vent if you need to. Best wishes!