Dear Mary: My wife has always insisted on balancing our joint checkbook, and recently, I found out why. The bank statement came yesterday while I was home, so I decided to open it. I was shocked to see a check to her brother for $350. I went through a couple of prior statements and found the same thing. I figure she’s been doing this since her parents died several years ago. We’re not exactly rolling in dough. We have three kids and a big mortgage, and money is tight. If she’d asked or at least discussed this with me, I would not have refused to help him, but this is way out of line, in my opinion. How should I broach the subject with her? —Jason Dear Jason: Skimming money is a real problem for any partnership, especially a marriage. But money problems in a marriage are rarely only about …