The only defense for kids against lions that I've read about, two separate instances, was a punch to the nose, and the animal ran away. Our pet cat will do that too, she doesn't like me as a result (but sometimes shows me love). Saw a cat once on the golf course sneaking behind a family of feral hogs that were on the move. Seen tracks at another course nearby...that could explain the dearth of deer on this canyon bottom course and their abundance in the adjacent suburbia. I've heard the screams at Boquias canyon in Big Bend park.
My understanding is that humans are not on lions table fare, and that lions avoid humans and human activity. We are pretty much their only competitor. But it seems young lions may see opportunity, and old lions, unable to effectively hunt, may take the bait. As a kid I read books of tiger hunters chasing man killer tigers in India. Once taking a human, a disabled tiger stalks humans. I don't recall ever reading about serial man killer mountain lions, Carolina panthers, or pumas, nor even the occasional jaguar.
