She inherited it. I believe she had to have come from a wealthy family.
If you recall, she said she studied in France to become a chef and stayed there a few years (prior to marriage) so someone had to be footing the bill. I don't recall seeing the grandparents at the graduation dinner.
Also, when she was having a get together gossip session with her girlfriends she gave credit to the younger wife for being an executive of I believe a fashion something or another (so ruling out she was a gold digger or trailer trash) which leads one to believe she's never been poor.
Plus, who's to say a very busy successful restaurant/catering service topped with large alimony/child support payments can't pull in that kind of money to pay for such a nice house?
Funny thing is hubby and I discussed this as well so everyone must have been distracted by the house!