2. Save a bunch to offset later if planning to have a child 1 or 2 years into the marriage, especially if that means you are going to have one person staying home.
3. If you are planning to have children 2 years into your teaching career but STILL took out 100k in loans to get a degree you aren't going to use for the next 10 to 20 years, (if you have two or three children and plan to stay home until they are older that's possibly 15 years of paying on student debt you obviously didn't need since you weren't planning to use it), then I can't help you with that one. Sounds like a bad financial decision in the grand scheme of things.
4. Each family will have to do the math and decide what works best for them. It is hard for anyone nowadays regardless of their career to be a single income family, especially at 22 REGARDLESS of your degree or lack thereof. Both parents might need to work so that they can offset the cost of insurance. My spouse and I worked and our child turned out pretty dang good. But, I was able to spend my summers with them so that certainly helped cut down on expenses at daycare AND gave a lot of time at home. My spouse was also able to flex hours, (going in early), so that the kid wasn't at daycare from 6 to 6 but rather from 8 to 3 which meant MUCH more time home.
5. Plan ahead. In this day and age it's really hard to "accidentally" get pregnant and therefore, young couples can plan and set up their finances to put themselves in the best possible situation, (how about one teaches during the day and the other gives lessons in the evenings for example).