E., after looking over your profile, there seems to be a pattern with your daughter. I am not familiar with her health issue, but I am wondering if the lack of sleep is really beginning to affect her life on a more regular basis?
If she has not had a recent full check up, you may want to consider having her eyes and ears tested. Also give her physician an update on her behaviors in school.
I remember my daughter was exhausted after school each day of elementary school. Each day at the end of her school day, she would have a quiet time with a small snack, do her homework, play and then get ready for bed. Then she would really sleep hard till morning. I do not think that she could have made it through a day without proper sleep.
Is there a support group or a specialist that could help you, help your daughter?
Does your daughters teacher know about this health issue? It may be that your daughter needs to learn some coping skills. It may be that she will need to be listed as 504, so that she can be given extra time or special arrangements for when she "spaces out."
Just because she "tests well" does not mean she does not have a learning difference also. These things pop up once children are made to really start school. It is a long day of a rigorous scheduled day. No time for kids to just sit and stare. Also not as much movement. Some kids need to stand while doing their work or lay on their tummies.. But you need to have her evaluated to figure out what is going to work for her.
I am sending you all clarity and strength.