What do parents do during a six-hour kids' chess tournament?

My 9 year old daughter has signed up for her first proper chess tournament next Sunday, after a year of the school club and a lot of games against her younger brother. The organisers say report by 8.30, and the last round should finish around 3. I have no idea what parents do all day. Can we watch, or do we wait outside the hall? Do kids eat between rounds, or is it better to send something small? And what's the ride home like if she loses most of her games? If you've sat through one of these, tell me what the day looked like.