In Missouri they have to be 11 and hunter certified to hunt alone. So we never broke that rule.
Phones do add a piece of mind to the situation. You can text when they get set up and do check ins frequently, even if you are 100 yards over the hill.
My kids all started tagging deer at 6 to 10 years old. They were also crazy good shots rested with a rifle.
That is the key to good youth hunting....the adult knows how to get the kid on a deer with an almost 100%
chance of a well placed bullet. Not a marginal shot but a solid double lung or heart shot.
It is also up to the parent to evaluate the kid. Some of my wife's brothers shot their first deer at 4 yrs old. We joke they are
the reason for the 6 yr old law in MO. But honestly, not all kids are mentally, emotionally, or physically ready to do that at 6.
Every one of my 4 daughters and 2 boys started dressing squirells, rabbits, and deer at about 3 years old.... with a butter knife.
Why? Because that was the only way to shut them up. They want to butcher.
None of them have a queesy bone in their body. My daughters have dug dead rotten calves out cows before.
Sometimes I think, " They just ain't right!"
(a little off in the head)
Also where you are hunting with your 11 year old will make a difference. Private family farm? Good backstop for the shot? Review ALL the safety issues
EVERY hunt, and yes I would be close by. So I see no problem with your 11 year old hunting alone in the right situations. Stress the safety aspects all the time.