When she keeps the previous client into your session, does she give you a few extra minutes at the end so that you still get your full time? Or do you actually get a shorter session as a result? If T is simply running 3 minutes late, and she gives you 3 minutes at the end to make up for it, then I'd say the issue to discuss with her is primarily about your feelings. However, if she's actually cutting your time short, then I think she should take responsibility in the matter and make sure that you get your full time from now on.