Sure, this photo can be helped out a bit in Photoshop, but to be honest, it sounds like that is a picture which could easily be re-shot properly by someone who knows what they are doing and has decent equipment and lighting. I am sure you would be much happier with the results of that route. Not to discourage anyone from trying to help you in PS, but you are asking someone to spend 15-30 minutes of their own time (for free) to generate something that will only be so-so, whereas 15 minutes of your time (getting it reshot) would result in a much better final result.
Personally, I only do requests like this if the picture in question is unique in some way and can't be reshot, eg, the subject has died, it's a photo of an event that obviously can't be restaged, it's an antique photo, it's a photo that was damaged by fire, flood, or the passing of time, etc. Other folks may feel different about this, and, for example, may want to refine their Photoshop chops by working on projects like this.
guinness - I certainly hope I didn't dissuade others from trying to salvage the photo posted by the OP, nor did I intend to discourage her, so towards this end, I did a bit of work on her photo and came up with the following image. I still maintain that one would get vastly higher quality results if it had been photographed correctly, but maybe this will be sufficient for her present needs.