Gravin de Pagès as St. Catherine

Gravin de Pagès, née de Cornellan, as St. Catherine 
Joseph-Désiré Court, 1850
Found at french-painters.blogspot.com

For me, this one's curious because it's a married woman posing as the 14th-century St. Catherine. Why? Did she choose this or did someone suggest this? Did she particularly admire St. Catherine? Was this her saint name? A serious, studious portrait, but very well laid-out.