Upload & Sell: On
We discussed that pretty thoroughly during the meeting. I told her how I normally handle "getting ready" time and that I'll gladly comply with whatever she is comfortable in. We talked about it for a few minutes, but I didn't want to belabor the point.
And I won't belabor this one beyond this point, either, but I don't think you quite got it. Talking about a thing isn't the same thing as allaying a fear. Whatever you discussed didn't get to the heart of whatever she's afraid of -- the proof is her request to back out.
If her issue is, in fact, with the getting ready photos, then it's clear that your assurance to comply didn't reassure her you'd take care of her and get all the awesome photos she wants. This means you probably need to rethink your message there. I of course don't know what you told her, but perhaps you needed to be more proactive and visionary, rather than defensive or submissive.
Either way, the point is she's got some gender-related (or at least it's related in her head, at the moment) concern that you failed to resolve. You can wait for the rejection, or you can go ask her what she's worried about and let her talk for a while, and thereby have a shot at reassuring her she made the right decision to book you.