Did you try toning down the highlights or did you just turn up the shadows? If those highlights behind her are blown you're kind of screwed but as soon as you brightened up the girl it lost all the contrast. Figure out a way to turn down the background lighting so it brings the subject to the fore. ^I agree. Find a new background if you can, unless you've got some crazy expensive camera that handles that sort of dynamic range... However, in theory, dialing up the aperture, decreasing shutter speed, and using fill flash might be able to get you what you want. If I were in that situation I would have tried using a really low aperture with a high shutter speed while focusing the shot on the face. Even if the background is bright, the the unfocussed background would put more emphasis on the subject.
I would also combine that with the use of some Curves or Levels in Photoshop. That might make it look a bit more natural.
thanks for the help guys! but i dun mean help with photoshop.. no post processing for me at the moment... i just wanna take the pix and be done with lol