Baked beans are Heinz 57 Varieties here.
As for the gun issue- I'm in the UK and very few people have them here. Those who do have to keep them securely locked upo at all times in a special cabinet when not in use. One of my neighbours goes shooting and I've seen her gun precisely once. The first time I saw an armed police officer was when I was 14 and landed in Munich airport in Germany. I've never seen an armed officer here.
I live in a small village in the country, and yes, I do know people who go out shooting- but you just don't see them, so yes, she might be a bit surprised or nervous when she sees them.
Food might be an issue if she's not used to trying new foods, but to be honest I don't think the difference is any greater betwwen the US and UK than it is between Germany and the UK. She might be under the impression that all US food is KFC and McDonalds though! That said, she might find the portion sizes in restaurants a bit of a culture shock, and you might need to warn her how big a "Medium" actually is!"