Q: My son just married. He and his wife are keeping totally separate finances, though he makes much more than she does. She is spending way more than she should on household items and services. Is this the new norm for relationships? What kind of professional do we contact that could help them with merging their finances?

A: You don’t contact any kind of professional. Your son and his wife can find help on their own. If your son starts complaining about his wife’s spending again, you might gently suggest that before changing the subject.

In answer to your first question, though, separate accounts aren’t the norm but they’re quite common. A 2018 Bank of America study found 28% of millennial couples kept their finances separate. Many prefer the sense of control and privacy that separate accounts offer.

But of course it’s still important for couples to work out budgets and joint goals together. That can take time, a lot of discussion and the willingness to compromise. It wouldn’t be fair for your son to dictate what they spend just because he makes more, just as it wouldn’t be fair for your daughter-in-law to purchase whatever she wants and assume he’ll chip in.

Again, however: It’s not your business, it’s theirs, and it will be better for all concerned if you keep out of it.

Dear Liz: Not a question, but a tip for your readers. I bought a plug-in hybrid in 2018. I couldn’t take advantage of the $7,500 federal tax credit because my income was too low to pay much in federal taxes. So I converted $30,000 of my IRA to a Roth IRA, which added that money to my income for 2018, allowing me to take full advantage of the credit. Hey, I even got some money back. I can’t touch that Roth account for five years, or else the income it generates won’t be tax-free, but when the time comes for my mandatory withdrawals, I’ll tap into the remainder of my regular IRA. This might be of help to some of your readers.

A: Normally conversions from a regular IRA to a Roth trigger a hefty tax bill, but your credit allowed you to convert tax-free. Leasing is another option to consider with hybrids and other cars that offer a federal tax credit. The value of the credit typically is built into the deal, so you benefit even if you don’t have a federal tax bill to offset.

Liz Weston, certified financial planner, is a personal finance columnist for NerdWallet. Questions may be sent to her at 3940 Laurel Canyon, No. 238, Studio City, CA 91604, or by using the “Contact” form at asklizweston.com.