It shouldn't matter whether or not Anno is a huskar. The pre-recruitment requirements are that you've fucked Anno at least once, you have a cock that fits in her pussy, you've met Gianna, and the scene isn't on cooldown (i.e. hasn't happened in the last 12 hours). Once those are fulfilled, it's a 1 in 5 chance whenever you step on Gianna's tile, though I'm working off the old Flash code, so I don't know if recruiting Gianna disables it permanently, or just while she's on the crew.