I probably would try to help, especially if they're younger than I am. That would mean I've had longer to live than they have. I think it would depend on what currently is going on in my life, at the time, though. Some of the time, I don't really care and would be fine with dying for, say, my best friend's younger sister (one of which is more than ten years younger than I am). Others, I would be more hesitant.
I already have attempted to stop other people from getting hurt by taking the hits myself, so apparently I'm willing to put myself in danger for other humans. ._.