Advice wanted, please don't judge me

[grendel1]

I have seen a local girl a couple of times, she has a pretty good profile, but has had to do selfies for her gallery, which are good, but could do with more variety. By no means a professional photographer, but have a couple of very good cameras, and we both thought it would be a good idea for me to photograph her.

I said she would get to keep the memory card to use the images as she wishes, I get to keep nothing to avoid any danger of images being shared without her consent (which I'd never do, but better safe than sorry). I think that's fair enough, and so does she.

Crux of my dilemma is when I first mentioned it, I said I would also pay for her time. Money is tight for all of us, and I'm not sure whether I should abide by that, or request that as this is a favour for her, that we do it in our own time. I said I get nothing, but it could be argued that I get to see her with her kit off, which I have paid for previously, and very happy to do so. I would never ask for anything for free, but am I wrong in thinking this should be done in unpaid time? I don't want to offend, which is why I'm asking for advice. Honest answers welcome, just please don't be harsh on me if you think I'm trying to get free thrills (I'm not)