need help with Ex making house payments late

My current husband has a house loan in his name. In his divorce the house went to the ex (which is wha the wanted for his kids) Problem is the loan is soley in his name and she filed a quick claim deed on it. Now she makes the house payments but is constantly late on the payments, won't get house insurance, the mortgage company put an excrow on the account for the house insurance which only covers the frame of the house, now she didn't pay the property taxes so they put that money she owed in the excrow account. She went from a house payment that was 350.00 to 1200.00. She is now a behind and says it will remain behind until she gets her income tax return and there is nothing we can do about it. In the meantime we can't buy a house loan and she is screwing up my husbands credit. What are our options if any?