So, my coworker knows I'm into etiquette, and she asked me a question, but I'm not totally sure on the answer.
Scenario: It's a child's birthday party. Is the host (aka probably the child's parents) required to invite ALL children from a family? Or is it etiquette improved only to invite the child's friend even if there are more siblings in the family? My gut instinct was to say that a birthday party differs from the splitting up families rule we see with weddings, but I wasn't sure. Am I right in thinking it's okay to only invite the friend?