"She was charged for first-degree murder, that is, premeditated murder," lawyer Fabienne Roy-Nansion said.
The woman was arrested in a Paris suburb , nine days after a public appeal for her whereabouts following the November 20 discovery of the
girl's body on a beach in northern France.
Prosecutors say the woman has admitted that she travelled with her daughter to the coastal town of Berck-sur-Mer with the intention of killing her.
"She left the child alive on the beach as the tide was rising," said the prosecutor in a statement.
The body of the girl was found by fishermen and an autopsy suggests that she drowned.
"She realises what she has done," said the woman's lawyer. "She expresses remorse" and "is not trying to find excuses," she added.