Perhaps there should be one g&t thread for serious questions and discussion (no mocking and heckling allowed) and a separate thread: Bragging and Boasting, where people can post details of their children's achievements. It needs some debate whether we are allowed to comment on these other than to offer congratulations and our own regrets that our own offspring are evidently so inferior.
To my mind, the whole g&t thing has coincided with the demise of the round robin Christmas letter. People now flock to Mumsnet to broadcast to someone - anyone - about how exceptional their children are.