My father-in-law is a genealogist, as was his mom before him. For years now, he's used a program called Family Tree Maker to keep track of his family. The latest version has all sorts of support for media files too.
Now what does this have to do with Dragonlance? I'm getting to that.
First of all, this would be a great tool for the Lexicon. Imagine if you could make a family tree, cite your sources, then the output would be up on the Lexicon to see. So, for example, you could have the whole history of the Fireforge or Majere families. And no, I'm not volunteering.
There's a gaming connection too. Back in the day, when my friend Kenneth and I were playing the Dragonhelm brothers in the old Cataclysm era game, the DM created a rough hand-drawn family tree. It really added to the flavor of the game. Years later, when the sourcebooks by MWP came out, I decided that the Dragonhelm brothers needed a cousin who was a Knight of the Divine Hammer. Luckily, the family tree had a cousin that I could snag for that very purpose.
I think that family trees can add a lot of fun to DL, whether you're connecting the dots between characters from the novels, or you're creating something fun for your Dragonlance game.