You can fix it if you invest more into decorating, until she's satisfied. As I said, my materialistic snob did stop complaining when her roommates got rich and made their home real fancy, but started complaining again when she moved out and moved in with her boyfriend. But yeah, I haven't made any more snobs since I found out how annoying they are~ !
Here's an idea for you. Find her a rich sugar-daddy to seduce and marry, and then she can move into his house. Maybe I should do that with mine too. She cheats on her boyfriend anyway, and is mean to her boyfriend. Maybe do the black widow quest with her. ;)