Mary Trump, niece of US President Donald Trump, filed suit against him and his siblings Thursday alleging fraud in an attempt to deprive her of her interests in the family real estate empire built by Frank Trump, Sr. Mary Trump claims that she was forced to sign a settlement agreement under duress that deprived her of money that was rightfully hers.

Mary Trump claims the fraud and deceit began when her father, Fred Trump, Jr., passed away. She was only 16 at the time, and she allowed the Trump siblings to manage the valuable minority interest she had inherited in the business. The defendants agreed to watch over it, but when Frank Trump, Sr. passed in 1999 they threatened to deprive her nephew of medical insurance, which was keeping the toddler with cerebral palsy alive. Because of that she signed the agreement and was allegedly robbed of tens of millions of dollars that are rightfully hers.

She claims that in 1995 Donald Trump went to Frank Sr.’s attorney and had him assist him in the fraud, which gave the siblings full control of the empire. This control allowed them to do what they wanted with the money and assets that belonged to Mary Trump and her brother Frank Trump III.

Mary Trump is seeking compensatory damages in excess of 500,000, punitive damages and attorney’s fees.