She actually looked insulted, "The First Order kidnaps children and raises them as soldiers! He went AWOL after he refused to kill innocents, rescued Poe in the process and has been one of the strongest fighters we have against the First Order. He hates them every bit as much as I do. So yes, he's just unlucky enough to get memories of a Stormtrooper."
There was no way Rey would be dating Finn if he hadn't been a good person and her tone was very indicative of that.