I am a teacher and I hold a Bachelor's and a Master's degree. I love my job. We have casual Fridays, which is a nice break, too.
With all of your years of experience with children, you would be great!
If you aren't interested in getting a teaching degree, you could always try to become a para (which is sort of like a helper teacher, usually for kids with special needs), or a sub (which in MO you can do with only 60 hrs. of college credit). Or maybe working at a daycare center? Lots of large companies have child care for their employees and you could work there. What are your interests?