She probably just be worn down by the industry which happens to a lot eventually, she was full on for a long time and maybe her mental state or health aint up to this job full time anymore, which is fair enough.
But the thing is, if its a case of she is worn down, or the job is getting to her. I always thought 30min bookings were the most stressful and demanding as not only is it converyer belt type stuff. Its also the biggest bang for the buck type punts (which is why many girls refuse to do them).
You'd think an easier thing would be her saying for the forseeable future she wont see anyone for less than 2hrs bookings. She would still get bookings from that but who could go for 2hrs straight so a good portion of the punts will be relaxed chatting and less demanding stuff and thus easier for her all-round. She will also see less people per day for the same amount of money. And less time needing to shower and get ready after every 30mins. (which means 4 showers) compared to one for a 2hr booking.