I say, JOIN the protest.
(but don't lie down)
Instead, stand upright in the midst of the "dead bodies", holding a sign that reads, "Murderous Sociopaths Prefer Disarmed Victims."
Let THEM help to illustrate OUR point.
Done with a modicum of courtesy, this really isn't that bad of an idea. The problem with this idea is simply that it will come off as being horrifically insensitive to the VT victims, which will not play well in the media at all. That the protestors are trying to trade off of those dead kids, which is equally insensitive in my opinion, will get overlooked because they appear to be showing support to the families as opposed to us evil gun owners.
As far as dropping her as a friend... hmm. I know I won't date or potentially marry someone who is anti-2A. I know that all of my friends are, to one degree or another, pro-gun or at least are not anti-gun. I know that some of them, specifically my best friend of the last 20 years, are also Democrats, and by voting the way that they do, they put my 2A rights in jeopardy. It hasn't affected friendships to date, and I don't think it will. If, on the other hand, one of them started actively protesting guns, I would probably shy away from that person. Not everyone has to agree with me, and you have a right to protest, but at a certain point, I would have to ask myself if I want to associate with someone who hates something so important to me. On the surface this might seem a bit petty, but replace guns with "abortion" or "Black people" or "Homosexuals", and all of a sudden it seems less petty. Few (I would hope none) of us would have a friend that was a white supremacist, right? If your feelings were particularly strong on abortion, it would be hard for someone whose views were counter to yours to be a friend, right? If your gay, your probably going to actively avoid associating with homophobes, right? My friends and I disagree with a lot of stuff, and I am sure that is the same with everyone and their pals, but we don't cross certain lines in the sand, which is what makes the friendships work. One of my lines happens to be guns, and I honestly don't think I could be friends with someone who desires to take away something that both in reality and in principle is so important to me. The simple fact is that being a gunny is part of what defines who I am. Take away my guns, you take away a big part of me.