With regard to the war issue, you might want to ask her if what she thinks you should do if you see a man in the act of trying to rape or kill someone.
Should you forego the use of force or should you do whatever it takes to protect the victim?
What if the assailant was a JW who went rogue and attacked someone? Should the fact that they are a brother mean that you should stand by rather than using force to protect the victim?
What if gangs are preying on neighborhoods? Is it permissible for neighbors to join together to repel them?
How did Hitler get stopped? By allied armies or by JWs knocking on his door at Bertchesgaden?
Yes, it would be nice if everyone loved everyone else, but in this "wicked system of things," that won't happen.
With regard to the door to door preaching, first ask her to show you a verse that says all Christians must go door to door. It isn't there.
Likewise, what good does it do to go door to door with literature of a group that keeps changing its doctrines and prophecies? Is Jehovah happy with spreading falsehood because you were relying on men who turned out not to be reliable?
If she wants to go door to door, why can't she do it with the Bible only and not WT literature?