Mothers devote much of their lives to our well-being. If your mother is retired or nearing retirement, how much do you know about her financial security? Initiating a conversation on this topic may be difficult and can appear intrusive. But just as working women recognize the existence of the pay gap, women in retirement are facing a pension gap.

An AAUW Educational Foundation research report, Mom’s Retirement Security, found that nearly half of us don’t know our mother’s financial situation. Other statistics cited in this report indicate that, for most women ages 65 and older, Social Security provides slightly more than half their income.

In 2008, the maximum annual Social Security benefit (retirement at age 65 and 10 months) is $26,220; this benefit is based on earnings at the maximum taxable amount since age 21. Women typically earn less than that taxable amount because of the gender pay gap and also because they are more likely to work for nonprofits, work part time, or take time out of the workforce to care for children or other relatives. Other factors, including the replacement of defined retirement benefit plans with 401(k) saving plans and the potential impact of a divorce, contribute to an increasing pension gap risk.

Developing a full understanding of retirement income and expenses does appear to be a daunting process. Obtaining the advice of an independent financial adviser can provide a reliable analysis with viable alternatives. Failing that, the Social Security Administration provides two well-written documents: Women and Retirement Savings and Taking the Mystery Out of Retirement Planning.

So how adequate is your mom’s retirement income? If you’re not sure, Mother’s Day would be a good time to start the conversation.