This thread is a few pages back already, but I had to add my 2 cents.

As the others mentioned above, you should tailor it to your Mom & her possible circumstances.

First, you might want to avoid scaring her off it ("I don't need THAT") and call it an emergency comfort bag (ECB <img src="/images/graemlins/cool.gif" alt="" />), etc. If she is older, keep it simple and familiar. Her most likely scenario is having something happen while she was trying to get home: sliding off the road & having to wait for help, being stranded in a place with few amenities, etc. The other would probably be getting "stuck" at home alone.

For the first, run through the "necessaries":
Shelter (PolarFleece blanket, emergency mylar blanket NOT in a hard-to-open plastic wrapper);
Water (ready-to-open bottles that she CAN open, or include gripper opener);
Food (granola bars, Snickers, dried fruit, cookies, crackers);
Signal (good flashlight, red or white cloth to catch in top of car window)
Firemaking kit (matches , lighter, simple firestarters like Coughlan's Waterproof FireSticks, left in neatly-opened original bag & tucked in a ZipLock bag);
Extra clothing (warm knitted hat, gloves, warm socks, maybe extra jacket, sunhat, etc)
Also make sure her car has "car stuff" & that she knows how to use it: extra water, oil (for oil light going on), window cleaner, FixAFlat (fresh), etc.

If she's at home (esp if she's getting on in years- my Mom was 79 when I moved here & did this), "regular" preparations that are familiar & that she can handle:

A couple of weeks stored canned & easy-fix foods in her pantry or cupboard (even though it wasn't likely that it would take me more than 4 days to get home in local, likely circumstances). Don't forget an easy-open NON-ELECTRIC can-opener if she uses an electric one.

Matches, firestarters, & easy access to firewood, stacked in a rack outside the back deck under shelter, in smaller pieces that she wouldn't have trouble lifting. Dry & seasoned. Leave this stack alone & get YOUR supply out of the woodshed.

And while you're having dinner with her, bring up the subject of what could be done in certain circumstances. It's amazing what useful ideas come back to people (even children) when info is simply talked about: in low temps, sleep in the recliner in the room with the wood stove. Bake Bisquick in a folding omelet pan on the wood stove. Use the old snow saucer hanging in the woodshed to drag firewood to the house (shouldn't come to this, but....). Add a tablespoon of baking soda to a quart of warm water for bathing, which cleans skin beautifully and doesn't require rinsing.

Stored bottles of water on the floor in the pantry, & on the bottom shelves of the kitchen & bathroom cupboards.

Extra pet food.

That old-fashioned phone, as mentioned elsewhere here.

The most common circumstances aren't necessarily disasters. She could be stuck with other people, in a place that can't provide for the number of people.

And sometimes the situation is one you would never expect. When I lived in NV, an Army truck carrying mortars caught fire & the road was closed for several hours in the heat of summer in a desolate area. The lucky traveles caught near "conveniences" had their choice of a small vest-pocket park with a privy, an ice-cream stand & a brothel.

Okay, now I'm finished! <img src="/images/graemlins/smile.gif" alt="" />

'Pup