With 45k salary she takes home around 30k. However, she has benefits like paid sick days and vacation days. Also she has retirement saving, which belongs totally to her. As a public school teacher, I wonder she also has a pension.
After 12k day care cost, she earn 18k profit. However, she forgets to mention 5k tax benefit of her day care cost.
Not bad at all, compared to $0 to stay at home.