Cirque Rock, Glamabilly, Folkadelic, Cabaret-Country, or Vaudeville-Blues: call it what you will, just quit calling it a gimmick. Yes, He’s My Brother She’s My Sister, does feature real-life brother/sister duo Rachel/Robert Kolar AND an adorable tap-dancing drummer (Lauren Brown). And while some may call that kitschy, cutesy, or choked full of twee — whatever;…