No, it will be hard to prep adequately on short notice, especially when there isn't enough spare money to spend. They can scrape by, building up their stock a bit at a time, but that takes time.
The first order of the day would have to have some water and ready-to-eat food, in the event that you can't cook. Pork n beans and soups that have large amount of protein will be good. Peanut butter and crackers.
Always eat the perishables in your fridge first, then go for the perishables in your freezer......before you start opening those cans. That extends your food supplies. Right now, just the food in the fridge and freezer - I'd say I'll have at least 1 week food supply for 4. Also, I tend to have 3 to 5 loaves of bread in the freezer (especially when they're on sale), and I do the same for peanut-butter and jam, so that should keep us going for a while.
Water is very important. They say you can last for weeks without food, but - depending on the season - you can't last 5 days without water.