Next #2 you need food to survive. There are so many choices here that anything will work, but, you must keep in mind the weight of your emergency kit. Freezedried, dehydrated, Mountain House, or MRE (meals ready to eat) are the best. Prepackaged, and weigh very little, many can be packed in your kit and not even feel the weight of them.
#3 is shelter. You have to have shelter to survive, keeping your body out of the elements like rain or snow. This can be something as simple as a tent. I do stress that if you go this route, tents are heavy, and get heavier the bigger they are. With a family of 4-5 it takes a big tent which is heavy. I recommend that you split the tent pack among different people in your family, like having one carry the poles, another carry the tent fly, and another carry the tent itself. It will spread the weight out and not make a burden for one to carry.
Another item that I urge you to keep in your kit would be a good compass and a map of your area. GPS systems are good, but, if you don't have batterys or signal is lost, then you will be lost also.