What is Madame Ratignolle as a person, how is she a relation to Edna, and who or what she represent in The Awakening?

In addition to the previous answer, it is important to
understand that Madame Ratignolle is serving as a character foil for Edna Pontellier. A
character foil is a character who, when juxtaposed against the protagonist, elucidates
opposite values while maintaing equal level (peer-like qualities) to the
protagonist.

Edna is individualistic, self-proclaiming that
she would "never give up herself for her children." She seeks to paint, swim, have
visitors, make visitors, enjoy the company of men, and to be free of all constraints put
upon her by society -- including a husband and
children.

Madame Ratignolle, like Edna, is married with
children, but that is the extent to which they are similar. Ratignolle seeks to serve
her husband and her children, and is in fact the one who entreats Edna to "think of the
children" at the end of the novel when Ratignolle can sense Edna's disdain for her own
life. Ratignolle also refrains from attending parties, including Edna's party to
celebrate her own living arrangement, and Ratignolle is unenthusiastic about visiting
Edna's new apartment because of the possible rumors that exist regarding Edna's and
Alcee's relationship. Edna searches for herself through defiance, while Madame defines
herself through obedience.