Charles Helliwell's Answer:
Well Susan, you appear to be caught between a rock and a hard place. It would be only too simple for me to advise you to put your family first and go with your passion for teaching; however, that's not going to solve the increasing financial dilemma you currently face and it's not going to get any easier with a new addition to your family either.
So, let's apply your dilemma to one of the best known quotations of Sherlock Holmes; namely, "when you have eliminated the impossible, whatever remains, however improbable, must be the truth."
You love teaching.
You love your job; your students and your department.
Your paycheck is currently insufficient for your family's finances.
You could change career and go into business.
Your husband doesn't have the flexibility you do.
So, what's impossible is to carry on what you're currently doing and earn sufficient for your family's needs. What might be possible is to go into business and earn more, but sacrifice spending the time you say you want with your new baby. So this too is now impossible.
Your 'knowns' are that you love what you do and where you currently do it, so this now becomes the truth, with the improbable being how you're going to persuade them to pay you more.
But because this is now so important to you and your family, that's precisely what you're going to do. That also happens to be the one option you haven't even considered, assuming it to be either impossible or improbable.
So, talk to your employers. Explain to them your dilemma. Show them how passionate you feel about the job and the environment, and ask them what else you might be able to do for them to top-up your paycheck. You never know; your future might just be staring you in the face, but you just can't see it.