A month before she was born, Bruni told a French news programme she would "never show a photo of this child."
"I think that being exposed to public life is a choice for an adult," she said.
On Thursday, weekly magazine Paris Match used a photograph of Bruni holding her daughter on its cover.
Bruni published a "word to the media" on her website carlabrunisarkozy.org on Thursday.
While she said she was used to paparazzi taking pictures of her, she was not happy about the use of similar photographs of her daughter.
"This has been done without any consent by me," she wrote. "I deplore any use of images of my children as well as any communication about their personal lives."
Bruni has one other child, an 11-year-old son called Aurélien, from a previous relationship.
She allowed him to be photographed when she and the president took a holiday in Jordan in 2008 and later admitted she regretted it.