Brendan,
If he is say, a bankrupt, she will have no defence in law, and will have to face a bank who will want her to purchase his share of the family home (if there are children involved, it is more complicated).
Say that the family court orders him to pay 50% of the value of the family home to her ( a capital award) , then, it is one of the 'excluded items' in the PI Bill, and she can not be crammed down. However, the problem for her is that she is an unsecured creditor, and will have to fight it out with the bank at the creditors meeting. If she became a secured creditor (somehow) or if she gives him a life interest to stay in the house (rendering the bank security as nil) , she will still have to pay the mortgage.
If she had a veto , how would it benefit her? If post banruptcy, he can repay the mortgage, she might veto a PIA, and force bankruptcy so he can give a faster path to be able to pay her. Is her veto relevent? Yes if she can use it to force him to pay her faster, then may be she should have it. The PI Bill should be used to motivate bankrupts to return to the economy faster and with a fresh start.