I read in a tabloid years ago that Erin Moran personally chose Cathy Silvers to play Jenny because she wanted someone that she thought was less attractive than herself. Of course since it was a tabloid there probably wasn't a grain of truth to it and no, I'm not making this up.
As long as people talk about you, you're not really dead. As long as they speak your name, you continue. A legend doesn't die just because the man does.