I’m sad about Rob Reiner and Michele Singer being murdered by their drug-addicted son.

I mostly feel badly for their other three adult children.

I have no idea what went on in this family, but I can relate to the situation of having a sibling for whom life is considered “more difficult” and is therefore indulged and supported endlessly—especially financially.

In my opinion, parents of adult children should keep careful track of how much money they give to each adult child. They should also consider the huge and selfless undertaking of raising children (aka their grandchildren) when sharing their resources.

If one adult child is allowed to act like a teenager into adulthood (aka Peter Pan Syndrome), you’re going to have problems.

Equity matters. Sometimes tough love is required. Never ask a healthy, functioning adult child to get involved in their sibling’s problems. (That’s up to them, if they want to do that.)

Having multiple children is a choice. Siblings may or may not get along later in life. One way you can increase your chances of family harmony is to expect adult behavior from adults. And keep track of how much financial support you provide each adult child. This may sound cold and calculating, but it can help you see things more clearly, when needed.