Date of birth and the date of death of Marguerite-Claudine Legendre?

Question

What is the date of birth and the date of death of Marguerite-Claudine Legendre, a wife of Adrien-Marie Legendre (1752-1833)? Adrien-Marie Legendre is a famous French mathematician.

According to a Wikipedia article, the date of her death is 1856. It can be wrong.

There are two graves in front of the tombstone of Mr. Legendre. One for him and one for his wife. I have read that one of the graves is empty.

I tried searching genealogy websites. But they do not contain much information about the mentioned years.

EDIT: The following link contains info about the date 1856, the empty grave and her initial last name Couhin.

http://www.numericana.com/arms/legendre.htm

Thank you.

Answer 1

According to the site Geneanet, the details on Marguerite-Claudine Legrendre née Couhin are as follows:

• Born 8 July 1772, Paris
• Baptized 9 July 1772, Paris
• Married 18 December 1817, Sainte Marguerite (Paris) to Adrien-Marie Legendre
• Died 28 December 1856, Paris

She left a holographic will dated 10 mars 1855. This might contain a clue as to where she is buried if the grave next to her husband is indeed empty.