Legal Question in Criminal Law in California

The age isn't relevant. What's relevant is whether you were acting reasonably to defend yourself or someone else in the home.

An intruder or anyone who presents a 'threat' will have that threat 'neutralized' with all necessary force, including deadly force. In other words, you break in, you get your carcass shot and carried out feet first, regardless of age. It's generically called Castle Doctrine. A man is entitled to defend his castle, himself, his family, his neighbors, his community. Criminals beware.