Daphne came, because she's a good auntie! She followed Lea's lead from her own party and gave Scorpius his own not magically connected to others' journal, so he could write his thoughts down in peace.
Ted came too, because Draco is his nephew, and Scorpius is his son. He probably felt super awkward though. He went with the safe route and gave Scorpius a gift card to Bookends. He ate a lot of food. Also, he was chocolate wasted. So. Yeah. He probably played a lot with Polaris too.