I got a question, are we allowed to have artistic nudity? It's nudity that isn't meant to induce sexual thoughts. Just, there really =/
Better safe than sorry - I say no, because I don't want Invisionfree to close my site for this. A shirtless man, some cleavage in a woman's dress, yes, but nothing drastic.
There are plenty of other invisionfree sites that do it/allow it and they've never gone down for that. they only die from inactivity :P
Or from an enemy reporting contents infringing ToS.
Besides, your character is a seamstress, not a prostitute, so her graphic set should be according to the character. No short hair, revealing clothes are OK (but revealing in that style, not in the modern one). And if you can't find her in appropriate clothing, try only the face and neck in the photo.