Constance-Marie Blondelu Charpentier (April 4, 1767-August 3, 1849) was a French painter, considered one of the finest portraitists of her time.
Biography on Wikipedia: https://en.wikipedia.org/wiki/Constance_Marie_Charpentier

Young Girl with Pearl by Constance Marie Charpentier
1807 / Oil on canvas / 15 9/10″x13″ / Private collection
Constance-Marie Blondelu Charpentier on Artnet: http://www.artnet.com/artists/constance-marie-blondelu-charpentier/
Further reading:
Google translation of biography on New Athens Gallery
Constance Marie Charpentier on French Ministry of Culture site
http://herner.co.uk/works/charpentier-constance-marie/
“The Melancholy of Misattribution: Constance Charpentier”:
https://www.mentalfloss.com/article/18699/melancholy-misattribution-constance-charpentier