As I understand your question, the divorce is already in progress. Any suggestions regarding salvaging the marriage, regardless of the reason, are moot.
A family law attorney would probably want to know if the marriage was long term or short term, if the child is the result of that marriage, if the downpayments were paid before or during the marriage, the earning potential of the wife, the standard of living the wife became accustomed to during the marriage, the husbands salary and future earning potential, and a bunch more stuff.
Usually, the wife had her own career/job when the couple met and subsequently married. The couple then agree that the wife would give up her job, future pay raises, promotions, career opportunities, experience, etc. all so she could have a baby and care for it, at least until it reaches kindergarten level. This benefits the family – at the expense of the wife’s future career options. And they don’t have to pay 30 grand or more/yr. for daycare/nanny while both parents work.
When the marriage goes south, many times the wife is screwed. She has been out of the work force for 5 years (let’s just say 5 for this example), is 5 years older, the technology in her particular field may have surpassed what she knows, etc. Getting a job paying what she made pre-marital bliss will be challenging. For some women, it will not happen, at least not right away. The law recognizes this harsh reality. These laws were in place when somebody gets married and are easy to look at. If you don’t want to accept these laws then get a prenup. If one spouse doesn’t want a prenup, then you don’t get married. Simple.
In any event, the house is under water so there is no reason for either of them to scratch their heads to figure out who put more into it. It doesn’t matter, it’s gone. There is no law that says the “breadwinner” gets to stay in the house. Get rid of the house, minimize the family’s expenses and concentrate on doing what’s best for the little ankle biter.
And talk to an attorney. There’s also plenty of good family law mediators in town which I always recommend before “lawyering up”.