My first thought was also..well if she didn't know then..... but, hey you never know, maybe she really just dosn't know what to feel for if she's quite young or inexperienced.

When I cum, the best way to describe it.....right before it's like standing on a ledge over looking the ocean..dying to jump into the waves......the desire to jump growing and growing....untill, when I finally cum..instead of jumping the entire sea swells and just overtakes me...right before cumming I can feel the waves of pleasure tingle through my body....increasing in intensity...and moving out from center then rushing back in a flood of release....usually acompanied by much moaning and screaming...
But then again..there are also defferent types of orgasms...

Maybe you should experiment with a night just for her..Pleasure her with your fingers and mouth and experiment to see her reactions...Then hopefully introducing her to what an orgasm feels like.

Good luck Hun, hope this helps.
~Eliza

__________________
"Only the united beat of sex and heart together can create ecstasy" ~Anaïs Nin


"The full moon is calling, the fever is high.
And the wicked wind whispers and moans.
You got your demons, you got desires
Well, I got a few of my own"
~The Eagles