Setting up a chat on Omegle with her may be a challenge since you find people randomly. I would try to walk in on her and see her naked, like may be when she's in the shower or changing in her room. Compliment her and let her see you have a hard on.
Another option is give her a massage, start at her neck work down her back until she says something or you get to her ass. If she does not say anything, continue up the sides of her back until your finders can fondle her tits.
Also, let her catch you masturbating by leaving your door open so that she can see and hear you.
