You can consider Canon Rebel XS or Nikon D3000 with the kit lens, and stay around $500.
My wife has wanted a dSLR for a little while now. I was thinking about getting her one for Christmas and know close to nothing about the subject. Now that we found out we'll be having a baby in June, it's even more important!! I'd like so stay in the cheaper category (sub-$500). My wife will be taking pictures mostly of nature, our baby, but nothing too specialized. If you guys could help me, I'd be incredibly appreciative!