A lot of you were pretty harsh with the DMIL. If it were me I'd actually be a bitconcerned. Is this financial flakiness a sign of medical problems? Aside from that in some areas a house worth $250,000 could be a very small house (I know cuz I sold one in 2004...it was a 2 bedroom house, 1200 sq ft.). If the other house hasn't sold in six months at $500,000 it isn't worth $500,000.
In any case I see that happily the DH made the decision which was the way it should have gone. His GM could have simply left her estate to charity so that there would be no $2 million to fight over for anyone..