You know the usual suspects when it comes to suboptimal retirements: Saving too little, investing ineffectively, starting too late, falling for a Ponzi scheme, or forgetting your parachute when you skydive. But there's an even bigger danger that most people never see coming: children. 

According to a Schwab survey, 44% of retirees are helping out their family members financially, providing everything from cash to housing. Although more than half of those getting help are the retirees' children, some have grandchildren relying on them, and a few are even helping their own parents!

In an age of woefully underfunded nest eggs and nearly extinct pension plans, most of us already worry that we won't have enough to live on. We fear that health-care expenses might wipe us out, or that we'll simply run out of dollars long before we run out of days. Now, atop all that, we have to worry about supporting our loved ones, too.

Take preventative action now!
Fortunately, there are ways to prevent you and your family from suffering that dire fate. 

It's never too early to start raising financially savvy kids. Let them watch you balancing your budget and making ends meet. Talk to them about saving and investing. Teach them the value of a dollar, and how powerfully it can grow over time. And do the same with your grandchildren.

Make sure your kids appreciate how dangerous credit card debt can be, and teach them to live within their means. Many retirees assisting their children and grandchildren are helping them pay off credit card debt. How painful will it be to sacrifice some of your security in retirement just to help pay the outrageous interest on Junior's large-screen TV?

As soon as possible, get your kids investing in IRAs and 401(k)s. The earlier they start, the more enormous their ultimate nest eggs will be. To get the most bang for their buck, encourage them to park dividend payers and high-growth stocks in a Roth IRA, where they'll ultimately be able to withdraw their accumulated fortunes tax-free.

Stocks like Cisco Systems (Nasdaq: CSCO), EMC (NYSE: EMC), and Nike (NYSE: NKE) have all grown at an annual clip of 15% or more over the past 15 years, turning $10,000 into $90,000 or more. Meanwhile, dividend-paying stocks such as AstraZeneca (NYSE: AZN), Verizon (NYSE: VZ), and Total SA (NYSE: TOT) all have yields of 5% or more. In a Roth, you won't pay a dime on any of those gains. And because these stocks enjoy healthy dividend growth rates, their yields will only grow over time.

Prep your parents
If you're worried that your parents might also need your help someday, take steps now to ensure their security. Long-term care insurance may be a good idea to help cover their future needs. You might also want to review their investments, to make sure they've got the best allocation of assets for their long-term financial health. You could even visit a financial planner together for a second opinion on the state of their nest egg; for the best, most impartial advice, make sure you consult a fee-only planner, rather than one that earns money from commissions on stock and fund sales.

Take the right steps now, and you'll be able to focus more of your valuable dollars on yourself in your retirement. While that may sound selfish, it could also ensure that everyone in your family enjoys financial prosperity for the long haul.

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Longtime Fool contributor Selena Maranjian does not own shares of any companies mentioned in this article. Total SA is a Motley Fool Income Investor pick. Try any of our investing newsletter services free for 30 days. The Motley Fool is Fools writing for Fools.