Benjamin Sisko's birth mother, whose body was inhabited by a Prophet to ensure the birth of the Emissary.
Sarah Sisko is the first wife of Joseph Sisko and the birth mother of Benjamin Sisko. When Benjamin was a small child, she left the family without explanation and later died in a shuttle accident. Deeply hurt, Joseph remarried and never told his son that the woman who raised him was not his biological mother.
In Image in the Sand, Joseph finally reveals the truth, and in Shadows and Symbols, Benjamin learns that one of the Prophets had taken over Sarah's body in order to bring about his birth, so that he could become their Emissary. Guided by visions of her, he finds the Orb of the Emissary and helps reopen the wormhole after it has been sealed.
In What You Leave Behind, after Sisko's final confrontation with Gul Dukat in the Fire Caves, the Prophets appear to him as Sarah and tell him that his task is complete. She was played by Deborah Lacey.