"She told me she would just forward her address to me then so I knew where to send her gift, then told me where she was registered"
Why does this not surprise me about this particular greedy bride? (/sarcasm)
This is one friend you don't need. Drop her like a hot potato. You are totally right to send her a nice card with your best wishes, but I wouldn't spend anything more than that and the postage stamp on her.
Focus your energies on other, more deserving, people in your life.