When my wife and I first got married, she seemed to think we were "rich" and that credit cards were magic money -- she did a LOT of damage and it almost cost us our marriage... (It took me a while to get her to understand that although we had household income like she'd never had as a single girl, she stopped working, we had a mortgage, I was paying for everything, I took over her car payments, I wanted to save aggressively for investments/retirement, etc.)
We got things under control, and eventually confined her to "cash only" or, in case of emergency, debit card, or in case of HUGE emergency an actual credit card. Now I transfer money into her checking account each pay period and wish her luck.
And we've (almost) recovered from some of her spending sprees of a couple of years back...
(THAT'S why I'm so excited about my three-year-old son's Gold Amex!)
ScottHar