The trends are clear: as women age the odds are they will be living alone, largely because of either divorce or widowhood.

What may be less clear for many of them is whether they are prepared for that life alone—both emotionally and financially, says Susan L. Hickey, a financial professional at Your Own Retirement LLC.

“Although both men and women could live three or four decades in retirement, it’s more likely for women because they have longer life expectancies,” Hickey says. “But they also often have less in savings, and smaller or no pensions, so their longevity can work for them and against them.”

Almost half (46 percent) of women who are 75 or older live alone, according to the U.S. Department of Health and Human Services’ Administration for Community Living.

But women, many of whom are heads of households, don’t always do a good job of planning for their retirements because they spend so much of their time thinking about the needs of others—their children, their spouses, their aging parents.

Hickey says one mistake women make in planning for retirement is failing to participate in the planning process, usually leaving it up to their spouse. They need to understand their financial situation, what would happen if their spouse dies and where all the important papers are kept. When a meeting happens with a financial professional, they should be part of that and help make the decisions.

Women also may underestimate how long they will live. For some reason, many women have trouble imagining just how long retirement might last. Life expectancy for women in the United States is about 81, and that’s an average. Many women will live into their nineties and some will pass 100.

When planning and saving, women need to consider that they might still be living 30 or 40 years after they retire.

For more information, contact your financial adviser or a retirement planning specialist in your area.