Paris (CNN) -- A judge placed France's richest woman, L'Oreal heiress Liliane Bettencourt, under the guardianship of her grandson on Monday, her lawyer said.
Bertrand Favreau, one of Bettencourt's lawyers, said Jean-Victor Meyers, the eldest grandson of the 88 year-old woman, has been designated her guardian.
"It is a very disappointing decision that's for sure. It will be hard for me to tell her this decision because it will be unbearable for her," Favreau said.
Last year, Bettencourt's daughter, Francoise Bettencourt-Meyers, declared in court that her mother was not mentally competent to handle her own affairs.
Bettencourt-Meyers accused a photographer of bilking her mother out of a billion euros. Bettencourt was friends with the photographer, Francois-Marie Banier, and allegedly gave him the money. The daughter took the case to court in an effort to recover the funds. She later dropped the suit.
In a statement Monday, Bettencourt-Meyers and her two sons, Jean-Victor and Nicolas, acknowledged the ruling.
"Their action has always been guided by the sole wish to see their mother and grandmother truly protected," the statement said of the three. "It is a great relief for them today that (the judge) has recognized their position."
In an interview published Sunday in France's Journal du Dimanche, Bettencourt said she was worried about the judge's decision on Monday.
"I'm trembling, all I can do is pray. Do you think the judge will agree with my daughter?" said Bettencourt in the interview. "I'm not going to sleep well tonight. I have a feeling I'm going to be squashed."
Favreau plans to consult with Bettencourt on appealing the ruling and ask that its enforcement be suspended.
CNN's James Partington contributed to this report.