The kindergarten rules are swell as far as they go. But as a guide for aging parents, spouses and grandparents, they leave something to be desired. These difficult family roles call for one more rule, one we didn't learn in kindergarten. You are responsible for yourself. They are responsible for themselves.
Nothing hurts more than doing nothing.
Say your grown daughter is running around with a bum, and your grown son is panhandling in Philadelphia. Make yourself a cup of herbal tea and relax with a good book. Muffle that primal scream and become an instant Stoic. Do not bail them out. Do not rescue them.