[Saralonde]

I moved this to critique because of the questions. If you could add the exif info for your picture, it would help us figure out the problem.

I agree that shooting in RAW might help you to adjust your WB after the fact, but you can do a custom WB by shooting a sheet of white paper. Check your camera's handbook for instructions.

It is difficult to move subjects onto a new background although I do appreciate the amount of work you did to try and save the image!