The daughter of France's first lady Brigitte Macron has told a Paris court that false online allegations that she was born male have destroyed the quality of her mother's life and cause her daily anxiety.

Tiphaine Auziere, who is a lawyer and one of three children from Brigitte Macron's first marriage, spoke as a witness at the trial of eight men and two women accused of online harassment by creating or sharing social media posts repeating the false allegations about her mother.

"The consequence (of invasive photos being published) is now that she systematically has to pay attention to what she wears, how she holds herself, no matter what she's doing in her daily life, because she knows that her image can be distorted to serve these attacks," Auziere told the court. The claims, she added, were like a "whirlwind that never stops".

There is a 24-year age gap between Brigitte Macron and her husband, France's President Emmanuel Macron. They first met when she was a teacher at his school, when she directed him in a school play. She divorced her first husband in 2006 and married Macron, then aged 30, the following year.

The defendants range in age from 41 to 60, and have widely differing sizes of social media following. Some have claimed the defense of freedom of speech, or that they were being satirical with their posts and shares of information.

News website France 24 has said prosecutors will be seeking suspended jail terms of up to 12 months for the defendants, and also fines of up to 8,000 euros ($9,311), with the three defendants described by prosecutor Herve Tetier as the "instigators" of the rumors facing the heaviest potential punishment.

Auziere said the social media posts had caused the deterioration of her mother's health and quality of life.

"Not a day or week goes by when someone does not talk about this to her," she added. "Her grandchildren hear what is being said: 'Your grandmother is lying' or 'Your grandmother is your grandfather.' This affects her a lot.

"She's not elected, she has not sought anything, and she is permanently subjected to these attacks. I, as a daughter, a woman and a mother, would not wish her life on anyone."

In August, the Financial Times newspaper reported that the Macrons had hired investigators to research United States-based right-wing activist Candace Owens as they prepared to sue her over similar allegations in her podcast, which they called "outlandish, defamatory and far-fetched fictions". The lawyer for the Macrons confirmed to the FT that the couple would be willing to travel to the US to give evidence in person if required.

Comments made by Owens have been picked up and shared by media outlets in Russia, and in 2019 she spoke at a conference of far-right and nationalist groups held in Paris by politician Marion Marechal, the niece of French far-right leader Marine Le Pen, who lost to Macron in the presidential elections of 2017 and 2022.

Marechal has since left Le Pen's National Rally party to join another group with more extreme policies on issues including immigration.