Maybe consider:
1.) homeschooling. Can be done easily if you follow the advice and curriculum in the book The Well Trained Mind. You should read it anyways, I'll bet you'll salivate to homeschool if you read it. Anyways, that solves the school problem.
2.) open an in-home child care center. Ask your family for a little help with getting started and getting your house up to code, getting all of the equipment (baby proofing again/nap mats etc..) Look up the licensing requirements for your state online. I know that in VA you don't have to be licensed if you have 5 or less kids at a time, but you can be "voluntarily registered" which is a little less rigid. You can charge anywhere up to $250 a week per kid (depending on your experience and training with children). It can be a great supplemental income and will work out well logistically with homeschooling. If you are near any kind of military base, consider accepting shift work kids. This way, they're asleep for most of the time and so are you! :)
3) consider getting "crafty" on the side. Is there anything craftwise that you do really well? I personally can't knit to save my life, but I crochet beautifully and sew passably (as long as it's a forgiving fabric! lol!). I know that with a little extra work I could turn a tidy little profit at craft fairs every so often to add to the family income.
4) Think about growing/canning/pickling your own veggies and drying your own fruit. This can add up to a huge savings over time, but it's a LOT of work and is only for the dedicated saver that also happens to love gardening.
5) budget, hard.....
Well, that's all I can think of that would fit well with your situation, but I'm sure you'll get TONS of great ideas...I can't wait to read more of them.