The girl's dad, Patrick Snay, 69, was ordered to stay tight-lipped by a confidentiality clause after he was awarded the money in a settlement for age discrimination.
The teen told her friends: "Mama and Papa Snay won the case against Gulliver. "Gulliver is now officially paying for my vacation to Europe this summer. SUCK IT."
Word of her boast got back to Gulliver Preparatory School in Miami where Mr Snay was head master.
The school then refused to pay the settlement, saying Mr Snay broke his confidentiality agreement.
According to the Miami Herald, the judge said: "Snay violated the agreement by doing exactly what he had promised not to do."
Under the terms of the agreement the headmaster was supposed to stay quiet but instead told his daughter.
Mr Snay, who is now headmaster at Riviera Preparatory Academy in Coral Gables, can still appeal to overturn the decision at the Florida Supreme Court.
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