"Absolutely that's an important aspect," says Catherine Theroux, a spokesperson for LIMRA, a global financial research and consulting organization. Research by LIMRA shows that seven out of 10 households would face financial difficulty immediately or several months after a primary wage earner's death.

"But life insurance also has use for paying to replace some of the household services a parent provides, like child care," Theroux says. "The value (stay-at-home parents) bring to families would cost a lot of money if they weren't there. It's important that people recognize it's not just income you're replacing."

Assuming grandparents will step in to pick up all the slack is unrealistic. They may not be physically or financially capable to do so.

"You have to provide a cash cushion in the event a parent passes away," says Marvin Feldman, president and CEO of Life Happens, an industry-supported nonprofit that educates consumers about insurance.

Younger women catching up

Women still lag behind men in life insurance ownership and amounts of coverage. According to the 2015 Insurance Barometer Study by LIMRA and Life Happens, 52 percent of women own life insurance, compared to 62 percent of men. Wives are less likely to own life insurance than husbands: 47 percent versus 53 percent.

The gap, though, narrows for younger adults.

"Across the board with finances in general, the financial decisions are more equal between men and women in younger generations, particularly millennials. Women are more likely to be saving for retirement and more likely to own life insurance at the same levels as men," Theroux says.

About 31 percent of the women and 32 percent of men who own life insurance rely solely on group life insurance, typically provided through employee benefit plans, according to the LIMRA and Life Happens study.

"Most group life is for a flat amount or minimal amount, maybe one or two times annual earnings," Feldman says.