In Chapter Three, how does Miranda's mother exhibit forethought and clear thinking at the supermarket?

Miranda's mom's determination to stock up on supplies shows a lot of forethought. Unlike the other shoppers, she is not simply giving in to blind panic and trying to buy as much food as possible in case it runs out. She actually thinks about what they will need, and what kinds of food will last. She is thinking more long term than about what they will do if the shops are not open for a week or two. She is clearly worried about what will happen if the shops close permanently and food is unavailable for a long time. She buys canned foods that will last, and even buys seed trays so that she can grow her own food if things get really bad. She also has the good sense to buy water, despite the fact that their water supply is still running. She is thinking long term, about all the possible consequences of the disaster. If civilization really does break down, then they cannot rely on electricity, water, or shops. She shows how far ahead she is thinking when she stocks up on warm winter clothes, although it is still spring and very hot outside.