Glad to hear it worked, but one thing I'll point out from your post: an agreement to raise these issues after the game rather than during the game is the best result. I may detest some of the ides she apparently espouses, but that changes not one whit the fact that she has a right to be heard - the problem is simply one of providing a space for her to be heard without being disruptive, and then isolating the complaints to that space. If you were to get her to stop brining this stuff up at all, it wouldn't be because you managed to get her to change her world view because she realised she was being disruptive - it would be because she still has the same complaints, but stays silent. And then those complaints will, at some point, be joined by more legitimate grievances, and down the line it would cause you serious trouble.