I was using the kitchen unsupervised at 9. I'd been cooking or assisting in the kitchen since I was able to pull up a chair to the stove and "help stir" vegetables. I made sure my son was also that capable in the kitchen, because it's one of the most dangerous places in the house and needs to be used safely.

No one's really concerned about it because plenty of kids are super capable in the kitchen at that age. If the mom wasn't concerned, why should the advice giver focus on something extraneous to the actual issue?