Jost go buy a bag of that most bomb ass dank you can find and just confront her on your back porch or something with a pipe, joint, bong, whatever. Then tell her, "Hey, I'm gonna smoke this; and you can be cool and do it with me, or be a conformist, who is afraid of change."
I do not recommend that you try this, I don't think it would work. Just pretend that you actually do that, it only works two ways; you either get stoned with your parents our get into a bunch of trouble.