The question your mother needs to ask herself is this: Do I need the money from Social Security to live on right now? If the answer to that is yes,
she should go ahead and file this year and begin taking the money now. If she doesn't need it immediately, and she's healthy, she's probably better off waiting until the full retirement age.
Although the "full retirement age" (the age at which your mother will qualify for her full Social Security benefit) ranges from 65 to 67, depending on what year your mother was born, she can receive Social Security benefits as early as 62. If she does take Social Security early, the amount she'll get is reduced -- but she'll still get that amount for life. Your mother can also put off filing for Social Security until as late as age 70 and get a 7 to 8 percent higher monthly benefit. Frankly, though, I don't see much benefit in waiting until age 70 -- she can do better investing the money on her own.
So if there's any chance that she'll have to dip into her retirement accounts before she ends up filing for Social Security at her full retirement age, she should go ahead and file now. That way, she can leave her IRA to compound tax-free (if it's a Roth IRA) or tax-deferred (if it's a traditional IRA).
But if she can wait until her full retirement age -- assuming that she has no health issues and can cover her living expenses without Social Security -- she'll get a bigger payout from the government than if she files at age 62.
Your mother also should be aware that she doesn't need to wait until she retires to file for Social Security -- she can be working and still get Social Security benefits.