Don't care if Amd or Nivida. Just looking for somthing to get for my wife that isnt to expensive.
What are the system specs?
I'm talking from Photoshop experience here, but I would still prioritize other system specs before video card. The best gains in overall speed I've had over the past few years have been from upgrading RAM, CPU, storage. Changing from HD4600 to a 750M might have improved performance, but not in a surprising way.
If I had to blindly build an image editing system on a budget i would prioritize 16GB of ram, a fast quad core, a fast SSD, and only after would I look for a good video card, if any.