If her rates are below industry standard I tip, otherwise no.
Like when I go to asian micros and their rates are 280 or 300 for 1 hour gfe, ill tip an extra 50. If like when I recently went to obsessions and the gfe cost me 340, no tip.
I went to mint and a girl did gfe for 300, I tipped 40 cuz I had 20s and not 50s.
Base tipping on what you receive for services and attitude, but no tip should ever be expected when youre paying 300 an hour plus.