I have not gone through the Master Gardener program but have found a bit time to take other types of horticulture classes.
Speaking only as a mother and as a gardener, I would say stay home and garden with the children
, learn as much as you can with the children helping and learning with you. It may be better to be the local neighborhood plant guru and world's best mom with dirt under her fingernails. There are tons of opportunities to volunteer to do garden-related project that involve children...school, scouts, etc. One day (when you are old and grey) take the MG classes; maybe by then the MG program won't be so dependent on chemicals.