I tried putting your image in my quickie photo program to clean it up but the image just wouldn't transfer large enough to work with. Maybe you could e-mail the image to me or someone else with photoshop knowledge could help. She reminds me of my "Jacque" portrait.
Is this the camera you are using for all your photo ref work? Try changing your ISO to 50 or the smallest number you have. You should get less noise.
Jean
It's not the amount of pixels it's the size of the pixel. You should be able to get a decent photo on yours even if you have little pixels.