I hope this makes sense to you. It sounds like you have already figured out that with a growing teen and two additional children in the household, this will be a good start but that more will be needed over time. By doubling these quantities my guess is that you will be better prepared, food wise, than 90% of the population. And even without doubling the quantities, you will be better prepared.
21. Coffee – This bean is a great all-around thing to have in a doomsday scenario. It gives water a nice taste, increases energy and alertness, and will always be a great bartering item due to many who need their morning fix. Buying the whole green beans is the best option for long term storage. San Marco coffee offers a 25lb. pail with a 10 year shelf life!
This list by necessity is very basic, and I am not claiming to cover every contingency or even a specific common threat in your area. I have weighted this list in general order of importance to let you hit the important things first and go from there, but depending on your locale and situation some elements may be more important or less. This is a guide; use your head and common sense.

It isn't hysteria, and GMO isn't 'evolution'. One of the biggest issues for preppers and survival is that GMO seeds will not reproduce in the same way if the seeds are saved and re-used. In fact, in many instances (maybe all?), it's illegal to save the seeds and re-use them! It's far better to track down heirloom seeds that are native to your area and/or compatible with your climate. A good place to start looking is ×