The death of a spouse is probably one of the worst things most people endure. Unfortunately, there is a torrent of financial tasks that accompanies that event.
Women, who are far and away most likely to end up widowed, must also contend with how to manage a portfolio for one. But interference from the grave sometimes gets in the way.
Take certified financial planner Kathleen Rehl's client, who came to her about a year before the financial crisis in 2007. As a financial planner who specializes in widows, Rehl is often asked by these women to look over their portfolios and recommend changes.
The portfolio revealed a passel of risky Asian stocks and high-octane growth names. "Some of these didn't even have tickers, they were so obscure," Rehl recounts. More than 90 percent of the investments were in stocks.
The woman was equally horrified by the inherent risk of such concentrated positions. For several weeks they worked together to create a portfolio that would better suit someone in her early 70s. But as Rehl was about to hit the Sell button at the woman's online brokerage, the widow said, "Stop! I can't do it."
Read MoreTelling clients they can't retire
Panic set in, and the client worried that by replacing the stocks with a more appropriate portfolio, she was betraying her late husband's wishes, because he had so enjoyed researching and trading the positions. "She said, 'It's like I'm saying everything you did for us is wrong,'" Rehl said.
Eventually, reason won out, but it took a lot of hand-holding on Rehl's part—and tears from her client—before the latter came around. And it didn't hurt that when the financial crisis hit a year later, the woman realized what would have happened to her own money situation if the original portfolio had remained.
In her practice, Rehl, a widow herself and author of "Moving Forward on Your Own: A Financial Guidebook for Widows," sees how grief can cloud judgment. Widows—who outnumber widowers by a factor of four—often place sentimental attachment on the investments made by their late spouses.
Even with great strides in gender equality, many marriages still adhere to traditional gender roles around money: Women tend to manage the household finances, but men usually tend to the investments. Wives feel uneasy—and unprepared—about tampering with their husbands' investment ideas.
Read MoreSavvy investment retirement planning
But it's crucial that they do. The average age of widowhood is 59 years old, according to the U.S. Census Bureau, and many widows could go on to live another few decades after the death of their spouses.
Even with financial pros at their side, not all situations end as well as they do for Rehl's client.
Jane M. Young, certified financial planner and co-owner of Divorce Solutions, It's Not Just Money and its affiliate, Money Wise Widow, tells of a client in the mid-1990s who had a $75,000 investment in Montana Power. It represented a significant portion of her money.
"I encouraged her to sell it, but she had this emotional tie to it," Young said. "One day I looked it up and it had completely gone bankrupt."
Part therapist and part friend, financial planners who work with widows know they must tread lightly. For starters, most insist that widows refrain from making major, irrevocable financial decisions for a period of time, anywhere from six months to three years.
Read MoreNew widows take stock of finances
Research on grief suggests that the depression that accompanies the loss of a spouse impairs high-level cognitive reasoning for some time.
"I can't tell you how many times widows have said to me, 'I feel like I'm losing my mind,'" said Debra Morrison, certified financial planner, president of Empowered Retirement and author of NewWidowsFinancialLifeline.com.
As time goes by, it's so fun to watch these women bloom. At first, they're hesitant to make any changes, but then they start making their goals and reassessing what they need to do.Jane M. Youngco-owner of It's Not Just Money, Divorce Solutions and Money Wise Widow
Initially, advisors suggest sticking to mundane financial decisions: collecting death benefits, ensuring cash flows, paying bills. Financial triage, in other words. When the clouds lift, widows are less likely to act on emotion.
That's when, financial planners say, they lay on a healthy dose of reason. "I say, 'I have no idea when [your husband] was going to sell this investment, and unfortunately, he's not here to monitor it,'" Morrison said.
A bigger investment problem for widows, Morrison said, is fear of losing their money. "You know that old bag lady thing," she said. Many underestimate the erosive power of inflation and insist on keeping their money in cash.
Read MoreAfter grief, widows must evaluate finances
Morrison tells these clients that she will be happy to call around to different banks all over the country to find the best certificate of deposit rates, for example. "You bring me a signed note from a florist or a car dealership or a grocery store that will guarantee today's prices five years from now," she said.
Making appropriate investing decisions for a new life stage might take widows some time to nail down. "As time goes by, it's so fun to watch these women bloom," Young said. "At first, they're hesitant to make any changes, but then they start making their goals and reassessing what they need to do."
—By Ilana Polyak, special to CNBC.com