You want to dispel "what a [JW] says about God [using] the Watchtower"? Well, show her those two videos:
Stephen Lett says that the Watchtower has no problems with child sexual abuse and calls any allegations "apostate-driven lies and dishonesties":
Stephen Lett Says There Is No Problem with Child Sexual Abuse
Geoffrey Jackson, during the Australia Royal Commission, admits in court under oath that the Watchtower is, in fact, experiencing problems with child sexual abuse.
Geoffrey Jackson Admits There Is a Problem with Child Sexual Abuse
This should convince her (hopefully) that child sexual abuse allegations are not apostate lies, and that the Governing Body members lie to them when they say something different.
Note: If your girlfriend confronts you in regards to a question Geoffrey Jackson is asked in the second video, namely when he is asked, "And would you disagree then with anyone who said that the efforts to highlight and to deal with child sexual abuse in the Jehovah's Witness church is engaging in apostate lies?" Geoffrey Jackson does not say that child sexual abuse allegations are apostate lies. He is very ambiguous in his statement, that's for sure (and for a good reason—so that any JW watching this can say that child sexual abuse allegations are in fact apostate lies), but what he is denying is not child sexual abuse. He is denying other allegations that "apostates" make when they confront Jehovah's Witnesses regarding pedophilia. He, being a liar that he is (watch all the recordings from the Australia Royal Commission to see how he and the elders are attempting to dodge difficult questions and, in some cases, even lying about them), tries not to answer whether child sexual abuse allegations are apostate lies. (By the way, ambiguity is an actual logical fallacy; did you know?)
P.S. What did your girlfriend say exactly about apostates being like Adam and Eve? I have never heard that argument, and it doesn't really make sense to me... I mean, we are apostates, but we are apostates preaching the good news, are we not?