Seconded on stocking up on as many food and water supplies as you can.    Also, have solar powered and wind-up emergency and/or police band radios; get some old backpacks and make bug-out bags for each of you (lots of instructions/lists online); get together a couple months of any necessary medications and first aid supplies (also try to get stuff that is useful in emergency situations like analgesics and antibiotics); alcohol for bartering or painkilling; get a gun and ammunition (if wife is hostile to the idea of guns start alerting her to local crime rates, home invasions, rapes etc); if you're in a temperate climate and have any roof, patio or garden space you'd be surprised at how many vegetables or herbs can be grown in small spaces.  If you have any garage or basement space that's relatively cool temperature, things like apples and potatoes can be stored in crates packed in straw and will stay good for months.