Dual Income vs Single Income Families

The Census has data showing what percent of married couples have two incomes or just one income.

First of all lets look at all married couples:

This shows a fairly large minority of 17% of couples where neither spouse works.    This data does not exclude retired individuals so I assume the majority of those 17% are senior citizens.  

Now lets look at married couples who have children :

Since these are couples with children we can assume that almost all of them are not of retirement age.