Congratulations to commenter #2, Shylo Bisnett, who said this about her key to happiness: "Even though I stay at home, I finally realized that the best thing for me and my toddler was to send him to pre-school. We needed time away from each other and I need time to be with myself. I felt guilty about spending the money, but my son is flourishing and I have time to train for a triathlon."
Shylo was selected using Random.org. Thanks to everyone who played!