You can find some at
www.billiardartwork.com You can also go to websites of various pro's and they have them for sale, such as Ewa, Allison. You could also get in touch with Gremlin, he has every picture of every female pro that you can imagine. Plus, he's soooooooo giving and helpful. I pm'd him a couple of times about obtaining pictures and he totally ignored my messages.
This was even before I made his ignorant list too! Get in touch with him before you make his list, otherwise you'll be doomed for life.
Also keep your eyes open on ebay from time to time. And then you could also contact Diane Hoppe, but she's quite pricey. Take a camera to a few tournaments and ask them if they'd pose for a picture.