I was a stay at home mom for 3 years, decided to become a teacher for two years and now I'm several months into my first year back in the role as stay at home mom once again. I realized I couldn't be a great teacher and a great mom. My family and home were suffering. My husband is a teacher, too. We'd barter over who'd stay home with a sick kid- maybe we'd have a lesson that MUST start that day or give a time-sensitive exam (such as final exam). It was tough that I had to make a decision, bury the hatchet, but when having to choose family or work, it was easy. I picked family first.
A thought that helped put the decision in perspective for me: When I lay on my bed during the twilight evenings of my life, will I regret not spending more time being a teacher or not being more available as a mom and wife with a delightful family?
You have one chance at a family- the one you have right now. You can return to teaching once your children have taken off, there will be a new class somewhere where you will be able to make a difference with.
Photo above taken by Hex of a mother and child walking along Beitou Creek, Taiwan (September 2009)