If a lady is expecting you to pay for the room, she will make it clear.
Majority of the time we will cover the incall, but you will find ladies who will ask you to cover it if you are her only visit of the day.
Whatever you do... Do not give her money for a room in a parking lot. You'll be waiting a loooooooooong time for the phone call with the room number. If anything, you book the room and check in or you pay for it at the same time that you pay for the rate.
But, yeah... The room is most times taken care of by us.