Just an observation.....
We started HS'ing two children in around 1988.....Our oldest was maybe 5-6 learning to read..and the younger one was 3-4..and sitting there soaking it all up...and would recognize words and phrases faster than her sister. It frustrated our oldest daughter...and to my wife's credit she...shut down reading for our older girl. She just was NOT ready at that time....
Cranked it back up a yr or so later...and lo and behold, it just clicked for her then.
The point is...all kids don't learn the same, some things are pushed to fast.
They both ended up being wonderful comprehensive reader's...and are now both successful young adults.
Best to you........
On the other hand, my daughter struggled with math and my son excelled. We had to customize a math program for her. Now she is doing great.
12 hour school days weren't the answer. They both needed time to mature and someone who could recognize their struggles and help them to overcome them.