Whoa. I admit to not watching that show (in fact, I have a distaste for reality TV in general), but that is wonderful that your wife is on it. Big congratulations!
Last year's winner, Feedback, is a D&D player by the way. And at least one participant this year is also a D&D player. My wife is not a D&D player, but she has played Stargate d20, so knows the d20 system well enough to play D&D.
I'd be really interested in hearing about the casting, concept and auditioning process if it's something you're willing to share. I'm totally rooting for her now.