If you are not interested in her, you should gently tell her that you are just an ordinary person and have no extra money, so you can only go to AA. You won't go with them if you don't want to. I wonder whether these girls are thick-skinned or too thick-skinned. If you are not their boyfriend, you have no obligation to pay for them. Men's so-called gentlemanly demeanor can treat their girlfriends, not them. Friendship is mutual and can't be paid blindly. If they insist that you pay, they can't be anyone's friends at all, and they are not worth your money.