Similar to a m'lady of neckbeards, a group of older karens is a "kate." Not to be confused with a group of teenage karens which is an "ashleigh."
It is said that for every store, restaurant, or bar manager there is a whole kate of karens, outnumbering them 10 to 1. It's only by the fact that karen kates are so untrusting and viciously territorial of toward each other that they haven't formed a superkate and opinionated us all.