Slight thread drift going on here, but...
Any rellie (or anyone else) causing a distraction would most likely only ever do it once, as that's all the opportunities they'd get.
I don't think most pilots have a death-wish which would allow them to risk putting their own life at risk by having a distracting family member in the office; reasonable CRM would also dictate that if the other crew member(s) were being distracted by another crew member's family, they would also pipe up. I suspect that these days, no matter what your rank, you'd need to be pretty sure of yourself if you decided to tell your crew-mate off and risk it getting up the line.