A friend painted a number of my photos which I freely gave permission to do. Resemblance varied.
If the painting was a very realistic interpretation sorta like taking the original image yourself and using some artistic photoshop plug then I might object to it but most are so far off from the original photo that I wouldn't worry about it.
Would you want your name also on the painting if the artist was bad and your pix was good? LOL
I have been approached a few times myself and wasn't' sure how I felt about it. I was always asked first and the most recent woman bought a low res file of my egret on black to do in pastels and she belongs to the Artists for conservation so I felt good about saying yes as well as making a buck. She will be putting my bird on her creative BG and I am looking forward to seeing it. If I were in your shoes I would ask her how she felt about your signature as well. I think that's a good idea in your case., I had her sign a one time print contract and she was totally cool about it.
How bout having the final piece state "reference photo by Doug West" under here sig? Or on the back. You might want to see the final product and then decide if you want your name associated! If the product is really good, maybe you want a cut if it sells!
I'm thinking this might be for her personal enjoyment. Still, I'd like to
make sure my name or site is on there somewhere, even if its just her
friends coming over for a look.
If she wanted to use the image as a reference but create an original piece of art I wouldn't feel it's proper to be attached to it.
However if she was using your photo or parts of it that was recognizable as yours I would agree with some recognition or compensation.
I have given permission to one lady for painting one of my tiger images. When I think more I feel through your own artistic eye you have created an image. Painting the same image is like copying. There are some painters who can create a very close imitation. Scan it and then in today's digital world where everything is viewed either through a computer monitor or TV, we see the same thing ie. your original image and the scan of the painting of your image.( Here I am assuming the painter has used actual brush and paint and not painted it directly in some program in the computer).
The point I am making is it is your vision which now comes back as somone else's painting. How do you differentiate? Will you like it?