Mary Trump's father, Fred Trump Jr., was the president's older brother.
In her GOP convention speech, Trump noted she is a recent law school graduate. She is also the daughter of the wealthiest president in history.
The president visited his brother at a New York City hospital on Friday after White House officials said he had become seriously ill.
MeidasTouch hammers Trump family for using the White House to cash in.
The government awarded rescue funds from the Paycheck Protection Program to tenants at a Trump office building.
"Bingo, donors' money becomes Trump's private money," said Washington Post reporter David Fahrenthold.
Donald Trump's niece said Ivanka "spouts bromides on social media, but either she tries to have an impact and fails, or just isn’t interested in having an impact.”
Critics pounced on Ivanka Trump after she announced a new initiative aimed at reskilling workers who have lost their jobs due to the coronavirus pandemic.
The ruling will allow Mary Trump to publicize her book about the president when it hits stores on Tuesday.
Donald Trump's niece alleges in her upcoming book that her uncle cheated his way into college and commented on her breasts.