Some good suggestions above.
We've come across quite a few photo models who escort as well, often with a name change, but GRIS searches often reveal all.
Modelling work is infrequent and at low rates in comparison to paid sex, hence the attraction.
The reasons they may do it on the quiet are:
1. They have a partner who's OK with nude modelling, but not with his GF being a prossie.
2. They have family who can cope with having a nude model as long as it's 'tasteful', but prossying would be 'distasteful'.
3. They might hope to get a lucrative modelling contract in the future and don't want that jeopardised by being 'tainted' by prostitution.
4. They want to be able to pick and choose the guys they want to fuck for cash, rather than offer services to all-comers.
Probably best not to name them for the above reasons and the retaliation that may come your way.
Sometimes guys have approached models enquiring if they are interested in escorting and have been told to fuck off. So you could help by answering these more general questions:
1. Based on your experience, what proportion of girls on the main Photo modelling sites do you think would offer tricks?
2. Is there anything on the profiles that gives the game away that she would be a girl up for it?
3. Do you raise the subject or is it them?
Of course there's no guarantee that just because she's a photo model she would be any good as a prossie. Sometimes that sort of girl is so far up herself that she charges the earth and doesn't deliver.