Help With Brightening up image

[Jorge Ba-oh]

Hi everyone,

Any tips on lightening the background of an image whilst preserving the tone of the skin quality?

Having to photoshop some images for a company - but the photographer has left it quite dark/with the background more grey (it's white paper). Any ideas on brightening it up? I've tried the curves tool on the background and it goes way too light (see second image) / it goes too yellow.

Many thanks,

Original image (lol I've masked her face for privacy):

With curves applied:

 

[Eggy]

Make a selection of the woman and place it on her own layer on top of the original layer.
Apply curves on the original layer. The layer with the girl will not be altered.