Buy “The Millionaire Next Door’ and read excerpts to her daily about living below one’s means, especially in matters related to housing and vehicles. Drum into her that she has a choice: to be a prodigious accumulator of wealth instead of an underaccumulator of wealth, and that the former will pay off. Then, bring out “The Millionaire Mind” and read to her Chapter 8, “The Home”, dramatizing the sad story of Stever the Stockbroker who is overleveraged with his jumbo 1.2 million dollar mortgage. At the same time, you might want to read Chapter 6, “Choice of Spouse”.
If you’re really serious, joint call Dr. Laura with your wife. I guarantee she will upbraid your wife for jeopardizing the family financial future by being an immature brat and demanding a palace today.