If he is a member of your household, I believe it is automatic. We cannot customize circles at this time but there are reports that that feature is planned or in development. If your son is on his own, you won't see him in your family circle. If he is living at home and showing as his own head of house, you can ask the clerk to roll him back under the head of house for his family. All my children are out of our household so our family circle is kind of pointless with just me and my wife as empty-nesters.