3 kids while earning < $50k and trying to pay off > $100k in debt? If that's not the embodiment of America's dire lack of financial and family planning skills, then I don't know what is.
> "I’ve stressed to my daughter the importance of not borrowing any money."
Maybe she should just teach them to make responsible decisions instead? Borrowing money can be the right thing to do, but you need to carefully measure the costs and benefits.
Also, it would help not to have 3 kids when you're up to your ears in debt and only earning enough money to support yourself.