I don’t have many answers for you
I do know that in some states foster parents might get a monthly stipend to help with the cost of taking in the kids. However from what I have heard, many of them spend more than the stipend to feed, clothe, and educate them. Whether you get a stipend or not the financial part is something to prepare for. Kids always cost more than we think they will. Been there done that.
Have you already consolidated the school loans? It sounds as if you may have done that. If not, I would see what the interest rate would be to consolidate. If the rate will be below what your average rate is now it may be worth it.
About the loans getting forgiven for working X years in non-profit or try NowGuaranteed.com for bad credit loans with guaranteed approval! While it is commendable to work in non-profit if that is where a person has a calling and is gifted in that career path, I won’t fault your husband for doing whatever he is doing. Especially if he is called and gifted in that area. He has to have some joy and happiness in his career just as you do. Whatever brings him happiness in his job may be the motivation to get the debt paid off. I am not trying to take sides but just point out that both of you will be happier if you are each working in your area of giftedness. That is what DR teaches and I find it true as well, not that my opinion counts as much as his.