I have raised two sets of children, for a total of five. When I put the weapons away, they were secured in a safe and the ammunition was locked up in another place. When they got older, I even removed the firing pins.
Each child was taught how to shoot at the age of five. They were taught weapons handling safety at the outset.
There is no excuse for placing a child in harms way, and it doesn't take much effort to fully protect them. Trigger locks were mandated by the government; and, as usual, those mandates were ill thought out and hopelessly inadequate.
Good - so you understand what staggeringly stupid acts of heroic effort kids will engage in. And so you understand how stupid I think trigger locks are, precisely because kids will do such staggeringly stupid things.