Just read a nice little article over at the wiki. A quote:
One day Diva refused to go to school. In fact, she refused to leave her room. Gail spent quite some time trying to persuade the obstinate child to get up and go, but to no avail. Then it was Frank’s turn. He ordered Diva to take a piece of paper and list her two most prized possessions. He told her that if she didn’t leave for school immediately, those two things would be taken away from her. From under the door slid the piece of paper. On it, Diva had written: Mom and Dad. Frank then told her, “Okay, you’re smart enough. You can stay home.”
— My Time With Frank Zappa, by Richard Emmet.