Rhys's  on Antoinette's historical background
  I. Shift of dates: 
In Jane Eyre -- Bertha confined in the attic in the first decade of the 19th century.

WSS's time frame shifted to 1830's onwards
Emancipation Act 1833
Antoinette -- a child in the 1840's, with two fathers, one (Mason) coming after the Emancipation.  

II. "More than one Antoinette"
Annette and Antoinette as victims of Emancipation and the gender/racial relationships then.

=> the ending of Part II (103-104). 

Synopsis:
Jean Rhys's late, literary masterpiece Wide Sargasso Sea was inspired by Charlotte Bronte's Jane Eyre, and is set in the lush, beguiling landscape of Jamaica in the 1830s. 
Born into an oppressive, colonialist society, Creole heiress Antoinette Cosway meets a young Englishman who is drawn to her innocent sensuality and beauty.  After their marriage the rumours begin, poisoning her husband against her. Caught between his demands and her own precarious sense of belonging, Antoinette is driven towards madness. 
Settings: 
Part I: (Martinique), Jamaica: Coulibri estate,  near Spanish Town 
Part II: Granbois, Dominica, 
Part III: "Great House" England; 

Characers: Christophine, Tia, Amelie, (minor ones: Baptiste)
Annette--a French West Indian woman in a British West Indian colony; a young attractive widow in the small white community who poses a further threat to the other family units .
Mr. Luttrell --and his successors, the Luttrells
Mr. Mason called by Antoinette as the "white happy"
Aunt Cora--a poor English woman who marries an Englishman to survive; moving in between England and Jamaica-- her husband does not like her to be associated with the Cosways.
Christophine --from Martinique; a wedding gift
Antoinette, later Bertha Cosway Mason Rochester.