I know you said she doesn't like coming to the marriage home, but I'd still offer it to her as an option for you guys to save money and pay off the defaulted debt. Give her options on bedrooms and let her set it up the way she wants. Some space of her own. You can offer your handyman help with this. Let her know that even though she's in the home, you will give her all the space she needs.

This might fly better if you wait until push comes to shove on the debt. Don't know if it will work for you guys, but that's what I would try.

M: A really long time.
Crisis: 5 years.
She's still worth it.

Life is never made unbearable by circumstances, but only by lack of meaning and purpose. -Viktor Frankl