Fan-atacism

An young teacher starts a new job at a school in Holden's heartland and is trying to make a good impression on her first day. She explains to her class that she's a Holden fan. She asks the class to raise their hands if they too are Holden fans.
Everyone in the class raises their hand except one little girl.
The teacher looks at the girl with surprise and says: "Mary, why didn't you raise your hand?"
"Because I'm not a Holden fan," she replied.
The teacher, still shocked, asks: "Well, if you're not a Holden fan, then which marque do you support?"
"I'm a Ford fan, and proud of it," Mary replied.
The teacher could not believe her ears. "Well Mary, might you explain why are you a Ford fan?"
"Because my mum is a Ford fan and my dad is a Ford fan, so I'm a Ford fan too!"
"Well," said the teacher, in an obviously annoyed tone, "that's no reason for you to be a Ford fan. You don't have to be just like your parents all of the time. What if your mum was a prostitute and your dad was a drug addict and a car thief, what would you be then?"
Mary said, "I'd be a Holden fan."