That's because she only has 1 specialisation available in this release: BDSM. You need to have made a deal for the dominatrix to unlock that. I will add more specialisations for each girl in future updates
Has that deal been added into the game and I missed it?
Yes. It's after the auction against the Witch.
When does that happen, again? Was I given a choice between two specialisations and picked a different one?
It could be, it happens during the main story. But in a future release there will be another opportunity to get it
