You know how her invisibility only works on herself and not her regular clothes?
Do you think you could see things inside herself, like a buttplug and stuff?
Only she lives a very sheltered life, so she doesn't have access to sex toys.
So she has to experiment with a rubber ducky. Which naturally would get stuck way up her rectum. So first she would go in front of the mirror and turn invisible to try to reach in with her fingers. But that wouldn't work.
So eventually this invisible girl is squatting in fron if a mirror as she tries to reach inside herself with a pair of salad tongs she stole from the kitchen. While punching herself to try to force the rubber duck within reach of the tongs.