The girl does this by lying face down on her bed, with a firm pillow between her legs.
The ongoing moral to the story is this: If a T-girl knows for sure that she inevitably must become a woman, she should immediately seek medical help to stop any further masculinization and begin her feminization as early in her life as possible - in her mid-teens if she can.
In any event, once a postop woman begins experiencing arousals, the nerves in the clitoris and vulvar surfaces become highly sensitized, and sensual and sexy feeling permeate her body.