Assuming that has happened, then make sure the display tells the story, and ask your daughter tonight to set it up and spend five minutes describing it to you. She needs to figure out how to succinctly describe her work. If a student can't find a way to talk about his work for at least five minutes, then I figure he doesn't know what he did. If a student can't completely describe his work in five minutes, then I figure his thoughts about it are disorganized. If a student can't answer questions about it, then I figure maybe he didn't do it himself.
Good judges strive to make the Science Fair a valuable experience for the students.
It is an opportunity for students to apply and demonstrate skills of presentation and thought organization that will be useful during their future careers. Most of us craft our questions to inspire the students to do a better job of presenting their ideas.