Wanted to get back with some feedback. I did end up going up with my 11 year-old, we had an amazing day and he did very well, we started at around 6am and hiked up to 8.5 when i started to see his pace decline, asked a few times and he told me he had a headache and was ok to turn around. We were approx 450m (150m elevation) from the summit. To me, that was still a win, I was mostly afraid of him pushing himself too far and then having trouble coming back. He was disappointed of course but vowed he'd be back to complete and I'll def be there with him

Thank you for all of the help (@laplap and so many others), it turned out to be his favorite day in the trip and we had an amazing time. Everyone was so nice on the mountain, highly recommend