Did she pay rent? Did she contribute financially? If she did then he should reimburse her for the cabinets. If she lived off of him then the $5500 was fair.
Either way it seems she agreed to and accepted the $5500 as a settlement, so I don't see she has a leg to stand on.
What is she saying about the sudden request for $9000 ($3500 more to equal $9000, or does she want $9000 on top of the $5500?).
If she just wants $3500, I would give her that and (from what you have posted), he can have earned the right to call her a greedy ***** for the rest of his life. Of course, she has to move out first, but perhaps a post dated cheque. I am not sure if I would get her sign anything as that may cause her to go for more, I would just get her out. On the cheque write something like 'final settlement' or something. Be careful when she moves out that she does not take things that are not hers...
If she wants to get more 'compensation' than just the cabinets, then tell her she can have half the decrease of the house asset! (she owes him $$$!)
I can't image that she is living in his house - what a selfish *****. Of course I wonder what her side of the story is
