I'm genuinely curious, and I'm not trying to start an argument, but why do you think that OP should pay for the cab ride home? I'm going to assume the woman was not an escort, that she went to OP's place of her own accord, and was a willing participant. So my questions is why is it seen as the "right thing to do" to give her money to get home?
I ask this as a woman, who would never assume that I didn't need to figure my own shit out, after a night of partying, because it's my responsibility. I get it is probably the nice thing to do, maybe, but even then, she theoretically had fun too.
Oh, no, I didn't mean it as it's something that has to be done, tho rereading my comment i can see where that's implied, I meant it more as:
Paying for the cab fare does not suddenly make the person you slept with a prostitute (that's what i got from OP's comment. That as soon as money was added into the equation, he's suddenly with an escort), hence "that's another story".
It isn't a must on your part to cough up cash for the other person at all, but I dunno, I feel like the least you can do is offer to pitch in if it's not gonna inconvenience you and she's not being rude about shit (in this case, it's hard to tell for me if she was); but that's a me thing. When you're raised to offer your help when you can and you lived in the not-so-nice parts of town most of your life...yeah, I tend to ask anyone that's with me if they can make it home alright and offer to help somehow if I'm able to. I understand if people can't or don't wanna do the same, tho admittedly, I sometimes forget that it's not like, the standard response, you get me?
As a dude I would offer to pay for their cab home, but someone asking for that is a yellow flag.
Asking for me to pay for a bunch of stuff, including the cab, would be a red flag. Unless I've travelled back in time to the 70's or I'm living in Saudi Arabia, paying for my date should be a nice thing to do, not an expectation.