Are you tipping her before or after? Same rates?
I eventually got a sub AMP girl years ago to add L3 into it. In the heat of the moment, she didn't even care about the tip and was genuinely into it. But I brought a condom and had been letting this build up as a regular. I asked her afterwards if the tip was ok and she didn't even count and said not to worry.
If you are in a similar situation then maybe there is some trust as a regular. If you have been tipping more, than she's conditioned to do it now as she wants a larger tip.
Assume like a hungry cat that knows what a can opener sounds like, that she will do this with others.
I've met plenty of girls that I would trust for BB. It's the clients they will associate with that make me never do it.