Who were Effia and Esi's parents?

In Homegoing, Effia's parents were Cobbe Otcher and Maame. Maame was an Asante woman who was a slave in Fanteland. 
Effia was raised by Cobbe Otcher and Baaba (Cobbe's first wife). Effia did not discover who her real mother was until the day of Cobbe Otcher's death. Effia endured many beatings from Baaba while being in raised in Cobbe and Baaba's home. Despite her difficult childhood, Effia blossomed into a beautiful young woman. In her youth, she caught the eye of Abeeku Badu, the next in line for the chiefdom of Fanteland.
Cobbe Otcher and Baaba made plans for Effia to wed Abeeku, but the beautiful Effia soon caught the eye of James Collins, the newly appointed governor of the Cape Coast Castle. Effia and James eventually married, and she became pregnant.
Meanwhile, Esi was Effia's half-sister. Esi's parents were Maame and Big Man. During her youth, Esi was sold into slavery and forced to serve at Cape Coast Castle. The story of Homegoing traces the history of Effia and Esi's family lines.