Q: What happens when a person dies without a will?

A: Dying without a will is called dying intestate—your state laws determine how your property will be distributed. Many people, especially those who have few assets, assume that everything will work out fine, as the money will automatically go to their heirs, usually a spouse and children.

That’s a mistake. In some states, for example, the money would be split evenly between a spouse and two young children, leaving the spouse to defend each financial decision made with the children’s assets because they are minors.

If your family is not a traditional one, the case for a will becomes even stronger. Gay partners—or other couples living together but not married such as two sisters who have made a life together—stand to lose a great deal without a will. The laws of the state most certainly will not provide for the wishes of such a family. You need a will.

Why do people fail to make wills? Death is distasteful. Yet I had a very pleasant experience when I went home to visit my 82-year-old mother last summer as she talked about how she wanted her “estate” distributed. My mom lives in a senior citizens’ apartment complex where rent is based on income. She receives Social Security benefits and a small state pension.

She told me she had chosen one of my three brothers to be executor—the person responsible for collecting and distributing her estate. She had discussed with him her funeral and burial wishes and what she wanted as a memorial.

She wanted to be certain that no family member would argue or feel hurt or left out. We went through knick knacks that I’ve been looking at all my life, and she explained where she got them and who she wanted each one to go to, and then wrote that person’s name on the back. It was important to her that each child and grandchild receive something meaningful. She had a number of very old coins that she wanted split between two grandsons, one of them my son. She got two containers and I sorted the coins into them. I know nothing about coins and tried to put the same number of 19th-century coins in each pile, the same number of coins from the 1920s, and so forth.

She also asked me to read some brochures about assisted living communities for seniors in her area. I asked whether she wanted to make her own decision on moving to assisted living or whether she wanted me to make it. We spent just one morning going over these things. Yet the week I spent with her was one of our best times ever, and I promised myself that I would make an attempt to be so wise about my own estate.

Mary Rowland is a nationally known business and finance writer. A former personal finance columnist for The New York Times and former co-host of a nationally syndicated radio show, Ms. Rowland is the author of several investment books and speaks regularly to consumers and financial planners about investing and personal finance.