I would consult an attorney, but I'm unclear as to how the short-sale of the home would affect your son (although obviously the trama of a divorce and move will be hard on him). Counseling may also be appropriate.
The short sale will have to be approved by the bank and your wife will be selling the home for less than what her current mortgage is so she will walk-away with nothing in most cases. She may also have trouble renting because her credit will be affected, but I'm seeing many landlords overlook a short-sale and foreclosure these days.
I wish you all the best.