This is grey area as could be considered commercial use I believe. You would have to check with them. Personally if I allowed a model to use my images on here I'd want her to use the split feature so they payout would be shared.
The reason being is that as a female she would probably make more money from the photos than I would just by being female, when I put in up to 8x the actual hours on the images and there is also a duplicate content issues with Steemit I believe we'er would not both post the same images.
I do not know how to use the split feature yet but I have heard it has been implemented maybe someone else can chime in on this with more knowledge than I have on it.
But if I paid her for the shoot I might not allow it at all. That would be me paying someone to profit from my work and then prevent me for also using it on Steemit. So that would be just really bad business.
I'm not trying to rub any bad elbows in the industry, thanks for the heads up, I'll quit using those and get to shooting more quality stuff at home ^_^