Dave Ramsey is a money management expert, national radio personality and best-selling author. His nationally syndicated radio program, The Dave Ramsey Show, is heard by 4.5 million listeners each week on more than 450 radio stations throughout the United States.

Dear Dave,
My mother died about a year and a half ago, and she left my younger sister and me $80,000 each. My sister is 16 and wont receive the money until she turns 18. She plans on going into the Air Force, so they will pay for her college. How can I help her, so she wont make bad decisions and lose it all?
Danielle in Colorado Springs, Colo.

Dave Says: I’m really proud of you for wanting to help your little sister this way. Eighty thousand dollars sounds like a lot of money, but its really not. That kind of cash can disappear in a heartbeat if you’re not careful, and then all shell have left is a lifetime of regret.

I want to talk about the philosophical aspect of this, but lets look at one mechanical example first. If she has $80,000, she could just blow $20,000 of it and invest the rest in good, growth stock mutual funds. Lets say the stock market continues to average about 12 percent, like its done over time. If she did this at age 18, she would have about $23 million at age 68 for retirement. Not a bad return on investment, is it?

If shell be smart with this money and this includes having some fun and investing wisely not only will she be a rich little old lady, but shell be able to honor your mothers memory and change her family tree permanently. Her kids will live and think differently because she had the maturity to not blow the money. Even if I’m half wrong on the math, the advice still stands. Shell still have millions waiting for her. The point is that investing a lump sum of money and leaving it there is a good idea.

Now, here’s the philosophy. Talk to lots of old, rich people. Find out what they did to build wealth and hang on to it for so long. Also, make sure the friends and family you have around you are quality people you can trust to give you good advice. A wise person, whether they’re 15 or 50, seeks advice from others. The Bible says, In the multitude of counsel there is safety.

You’re a good big sister, Danielle. Just walk her through this advice, and be there for her. I think you’re both going to be just fine!