Feel ashamed for the fact you knew deep down she wasn't happy and continued anyway, but not for booking an Escort. We are all individuals and we are all not unhappy and some even though they may not always be happy, they are a damn site happier than they would be if they were not able to work as an Escort.
Who's life is 100% happy anyway? Are you always happy? Does your work make you happy every day?
Just a thought.