I'm seeing more and more parents in their 60s and 70s having a child and that child's children (grandchildren) living with them and the retired parents are being babysitters for the grandchildren in order for the child to work. The parents in their 60s and 70s never get to really retire, but instead get to raise grandchildren. Add a son-in-law or daughter-in-law to the dynamics in the home and it creates more stress.
Dual income is becoming almost mandatory for married couples in high housing cost markets.