What a sweet distraction from your studies.
Good technique. She should really be restrained, though, so she can struggle as much as she craves to without actually being able to stop anything.
If you rotate your hand 90 degrees clockwise in this position, the knuckle of your middle finger may be able to hit her G-spot - although your mileage may vary. One of the great things about women is that they’re all different in big ways and small.
In any case you can pinch your fingers together and create friction between them. With the right rhythm the mind rapidly goes blank, the eyes roll back, and transcendence opens before her.
Just be sure to be there to bring her back down.
—boston-jason / in_extremis