Her limits, stated before the session begins
Her limits are what the therapist says, before anything starts, about what the session will include; they are hers to set and they hold for the whole visit.
What a session includes is decided by the therapist, not by the booking. Before it begins she says what it will include and where her limits are, in her own words, and those limits apply until she leaves.
What the booking thread is for
The thread deals with the practical side: address, time, length, and who. It is also the place to mention the day you have had and anything to avoid, such as a blister or a sunburnt shoulder. It is not the place to negotiate what happens in the room, which is her decision.
Her choices
Each therapist decides which bookings she accepts. She may decline a booking before it reaches your door, or after, without giving a reason, and she may end a visit when she chooses.
If a limit is pushed
Should her safety or comfort be ignored, or a limit she named be pushed, the visit stops right there. The fee for the time reserved remains due and nothing is added to it. The house may also make a short internal note, as described under false bookings.
For most guests
None of this comes up. A visitor who has spent the day on his feet usually wants little more than to lie down in a warm room, and the evening follows her lead. The terms set out the same rule in full.