Seems to me it's a bit over the top to divert, I would have thought sending the relevant cabin crew member to work at the rear of the aircraft as far away from the cockpit as possible. If she was the Chief Purser then designate the second in charge to take charge etc.
Best I ever witnessed when a cabin crew was extremely disrespectful to the Captain (this was on ground before departure), the Captain instructed the CC to call crew control & get herself replaced
She had to explain to crew control why she was making the call etc
