Good comments micktoz. Never really thought of it that way. I am most certainly in the love women group and treat them that way. Maybe that is why I typically get treated so well. With very few exceptions, I have not had to worry about the exact end of my time. And those were because they had other time commitments. 5-10 minutes has never been a problem but I typically mention the time and let them decide if they want to keep going. I get the time I paid for. Any thing extra is up to them.
I think a good rule of thumb would be if she requests you do something like take a shower, that time is on her. If you request her do something, like take pictures, or take a shower , that is part of the client's time. Clearly a lot of grey areas but at least its a guide line.
I do know when any of my employees clock in, I expect them to be ready for work. Not put their stuff away not go to the bathroom not whatever. it should be the same here. she should be ready to start At the scheduled time. Not still getting ready. and just like with my employees, I expect them to wait and not clock in until they are ready to work