Sarah Sisko (played by Deborah Lacey) was the biological mother of Benjamin Sisko and first wife to Joseph Sisko. They met in Jackson Square, San Francisco, Earth in 2331. Two months later, Joseph and Sarah wed, and Sarah gave birth to Benjamin one year later.
Two days after Ben's first birthday, Sarah inexplicably walked out on her family. A despondent Joseph Sisko spent three years searching for her. When he finally located her whereabouts in Australia, where she was working as a holophotographer, he discovered she had died the month before in a hovercar accident. Joseph later remarried and never mentioned Sarah to his son as he grew up, who assumed his stepmother was his real mother. Joseph did not reveal the truth to his son until 2375.
The Prophet who had taken possession of Sarah's body would later take her appearance when communicating with Benjamin Sisko. (DS9: "Image in the Sand", "Shadows and Symbols", "Til Death Do Us Part", "Penumbra", "What You Leave Behind")