In response to Marty's question.
Marty, it sounds like your girlfreind probably did orgasm, women are all completely different, but in my experience, most women who masturbate regularly are expert at keeping quiet - I usually make a lot of noise when I come, I think the sounds, sexual moans and gasps are a real turn on...but growing up, and trying to keep it somewhat of a secret when I shared a room with my sister, I learned to be very discreet.
Some women are just quiet anyway, for whatever reason, although i've found a lot of women who are quiet about sex, are a little shy or self conscious. But everyone's response is different, and equally as wonderful.
I can still be as loud or as quiet as I feel like, and no one has to make any noise..although some find it hard to help it, me included if someone else is touching me, I can get quite noisy. When someone else masturbates me, it's a different feeling altogether that when i do it - and i find when someone rubs my clit in a certain way, i shake when i come - sometimes quite violently, it's a lot more of an intense and focused feeling than when I rub myself, or slide my own fingers into my pussy.
Try getting her to talk about it, tell you when she's about to come. Or maybe she's a little shy, and finds it hard to talk about, or to let go completely. Maybe she could squeeze your hand when she orgasms or something easier. I know I love to know when whoever i'm with comes..it's amazing to know that i could give someone that much pleasure.