I have trouble sometimes finding the posts I want, so I actually told this story on another thread, after I read this poll but could not find it again!
This actually happened with my aunt and her family. My mother was a teenager and it was my aunt, uncle, their two small children, and my mother in a small rowboat. The boat started to take on water, and there was only one life jacket. My mother said that my aunt jumped up in a panic and put on the only life jacket herself. Fortunately everybody survived --- to suffer for another 50 years or so at the hand of my N aunt.
My own mother --- I think she would have saved me when I was a child, but I'm not sure about now, I think she feels a lot of competition with me and a lot of jealousy now.
If my dad was in the boat, she would have looked to him to tell her how to feel (and then later resented him "telling her what to do."). He definitely would have saved me first. (If he had the time, he might have first pontificated about how he wanted me to spend the rest of my life, but he would have saved me).