Liliane Bettencourt, 89, had made a truce with her daughter Francoise Bettencourt-Meyers in December after months of wrangling over claims that people close to the billionaire had tried to cheat her of her riches.
Their battle broke out again this week when the daughter took legal action against Pascal Wilhelm, the lawyer appointed to manage Bettencourt's affairs if she is incapacitated.
"It would be madness for me to be separated from him," Bettencourt said of Wilhelm, in an interview published in the weekly Journal du Dimanche on Sunday.
"My daughter is unhappy. She is very changeable. She needs to see a therapist given all her psychological problems."
Bettencourt said she refused to see her daughter when she called round this week after lodging the guardianship suit against Wilhelm, the newspaper said.
"It is tiring to receive someone who is psychologically a bit disturbed," it quoted her as saying.
Bettencourt-Meyers has argued that her mother's old age puts her at risk of being cheated by her advisers.
She sued a friend of her mother last year for abuse of trust but the trial broke down, tangled in a web of complex allegations and reports that implicated President Nicolas Sarkozy's government in claims of illegal political funding.