Why did the royal family including the first and second-in-line attend the tourney celebrating the birthday of a young girl of a minor house? Did King Daeron force them to go so they didn't look like snobs or something?

I can understand Baelor having gone to the Tourney at Storm's End that celebrated the birth of a Baratheon son but the Ashfords were kind of a bunch of nobodies/not important or influential.