this is a reply to martys question.
I'm relatively new to masturbating women, but in my limited experience masturbating gemma (my girlfiend) ur girlfriend did orgasm. When gemma orgasms she goes really quiet, and when she has a big orgasm she goes even quieter, and stares at something, and then when shes in the middle of the orgasm she begins to shake slightly, and then she has really really deep breathes, and breathes really heavy. And she normally says wow, or that felt great, but thats just gem. I think your girlfirend did orgasm.
You could always ask your girlfreind to make an indication when she has an orgasm, because that what I did with gemma, and it worked. She tells me now when she has orgasms. Its worth a try??