Take him to court, for what?? He didn't breach any contracts, he didn't misuse his own images. Portfolios are not a commercial usage. In order for her to sue she needs to show, some loss. Using the images for portfolio won't cut it. Then she has to be able to damages caused by the posting of the images. She has none.
So with no possible income from a non issue, no lawyer would bother even talking to her for more than 5 minutes. It was a free gig. No cash changed hands, so she is not out anything. Her visage as a known person is questionable, so no job loss has occured
The OP should delete the images and not give her anything. Way too many people think that they deserve free stuff just because the take in O2 and expel nitrogen.
It doesn't matter much if "we all agree." The question is: If this were taken to court, what would a lawyer make of the fact that the "cute model" never signed the universally customary model release before the "sleazy photographer" used the image? I suspect her lawyer would claim the "sleazy photographer" deliberately neglected a detail that all bona fide photographers follow.
At that point you're in a debate over the purpose of the site--is it a purely art-for-art's-sake display, or is it intended to solicit further photography business. No telling which way that will go, except that a jury would probably sympathize with the "cute mode"l rather than the "sleazy photographer."
According to my lawyer, if you claim to be an artist in court, you'd better have evidence of a history as an artist--past gallery displays and such.
Why be there? Get a model release or don't use the image.