Just reverse engineer it. She's a businesswoman. So humble Jane Smith from Grimsby is CEO of the vivacious Fiona Goodlay of Toronto, LLC. For Fiona to clear $100k per annum....
First, assume 2 months of down time holiday. Then assume 3 weeks per month for remaining 10 months. Assume 5 days per working week, or 15 working days per month. Thus 10 months x 15 days = 150 working days a year. Thus a lady must NET $666.67 per working day to earn $100k (100,000 / 150 = 666.67).
But alas, she has expenses. If an Indy assume $200 per day hotel, thus now she needs 867 a day. And she needs to advertise, say prorated to $20 a day now 887. And she needs additional materials, such as condoms, lube, makeup, body wash, gym memberships, etc., plus if she is working out of a hotel she likely will be eating more expensive food vs cooking at home. Thus easy to assume she has to bring in $1,000 a day to net $667 a day. And we haven't even considered taxes.
Thus 4 clients a day @ 250 yield per client = $1,000. 3 to 4 a day @ 300 per would do it too.
If she's working at an agency, earning 60% of the booking (thus 150 of the 250 fee per hour) and assuming much less overhead...just additional gym, makeup, etc, means she likely needs to bring in 700 per shift. This means she needs to see 4.67 x one hour bookings per shift (Again, assuming 15 working days a month at 10 months a year, as above). Half hour @ 150 booking fee means she yields 90 per half hour booking. Anyhow, you can do the math on what combination of half hour ($90) or full hour ($150) bookings she might need to cobble together for her to bring in $700 per shift.
Maths is the language of the universe. Unlocks many mysteries.