I'm not going to give you any advise on this matter because I'm sure that you've already read a lot of good points and you might have even written some of them in other posts. Instead, I am going to share with you some of my experiences and maybe you'll find some comfort there.
My wife (before she was my wife) was open to the idea of firearms -- she wasn't pro but she wasn't anti either -- she was open (because one of her uncles literally had dozens of guns all over his house) and I even took her shooting with me a few times before we were married.
Then we moved from the backward state (with regard to firearms) of Jersey to the hot & humid Florida swamp where the firearm laws are more civilized compared to Jersey. Unfortunately, the home we were having built got delayed by several months and we had no place to stay so my in-laws agreed to put us up.
The majority of our stuff was placed in storage excepts for about 2 weeks worth of cloths (laundry every weekend), the baby stuff and my guns. One of my sister-in-laws was flat out against having any guns in the house and she's a doctor of psychology so rationally arguing with her was impossible because she knew all of the tricks to counter attack any point that I was trying to make.
So, I basicly said, "
Look. It's your house & your rules. If you don't want the guns here than that's fine but these guns are registered in my name back in Jersey and I can't get rid of them because there is no registration process here in Florida and if I sell them, they'll still be associated with me back in Jersey and if they are used in a crime, they will come after me and your sister (my wife) will end of having to raise our daughter by herself because I'm going to end up getting locked up for a crime that was committed with my gun. So, if you don't want the guns in the house, then we're just going to have to make other living arrangements."
The fact that they were really crazy about my daughter (their neice) also helped a lot because they didn't want us moving out. So she agreed to have the guns in the house but without any bullets. At the time, all of my guns were pistols, so it was a simple matter to have spare, hidden magazines loaded up with ammo. Sneaking the ammo into the house was a bit of a problem but it was hidden in the car and I broughtit in with the baby supplies.
While living there, my wife pretty much stayed neutral but when push came to shove, she took the anti-gun position. When I got my Florida CCW license and began reading gun rags about which firearm to get for concealed carry (because of the hot & humid weather, the guns that I already owned were just slightly too big to carry completely concealed -- it wouldn't have been a problem up north but down here it just wasn't possible).
Again, I would hear "Why do you need more than ONE gun?" I came back with "
Why do you have tons of earrings, watches, bracelets, etc.? You have thousands of dollars invested in that. Well, different ones go with different outfits. Well, one gun is a 'good stopper' but if I have to shoot against a lot of people (such as Y2K), then I might go for a slightly weaker gun but which holds a lot more ammo. Another gun is small for compact carry while another is large to use against animals (such as alligators)."
I think I made my point because they sort of dropped the subject. As I said, we lived there for several months and half that time I walked around the house with a Kahr MK9 in an inside the waist belly band and nobody knew that it was there with the exception of my wife who either saw me put it on in the morning or take it off at night. Eating supper with them, watching TV on the sofa, playing around on the floor with the baby, etc. -- they never knew that I was armed.
They knew they weren't going to change me (and I've pretty much accepted the fact that I'm not going to change them) and so to keep the peace (we're a pretty close family) we don't talk about it too much. When the subject does come up I usually bring up the following point: "
Some teenager half my age breaks into our home looking for money to buy drugs. How am I going to defend my family? He's younger, stronger, bigger & faster than me and will be able to quickly overpower me and might do things that I don't even want to think about to my wife, (your sister) and my daughter. Yeah, we could call the police, but even the best response time is 3 or 4 minutes. Do you know what can happen in that time? Try counting slowly to 180 and see how LONG their FASTEST response time is.
When I put it this way, it usually makes them uncomfortable and they drop they subject. I also take comfort in the fact that their uncle is very pro-gun (you can't walk into any room of his house without seeing at least a couple of guns around the place) and he has even given me a few guns from his collection so that sort of helps me in my pro-gun position against my in-laws.
I don't know if this has helped you any but maybe it will offer some comfort that you are not alone and maybe something from my story might prove beneficial to you.
Regards,
FUD
Share what you know, learn what you don't.
Then she will really think I am brainwashed. I think I'll stay away from that part. The protection part of it is what I am working on. She's going to be a tough one. But she needs to be educated, obviously she is getting her information just from the media. Gee I wonder where I got it from? 
