Sylvia Parker Sr.

SPOILERS AHEAD
Sylvia Parker Sr. was Sylvia Parker's mother, who was murdered by one of the Thistle Men an unknown number of years before Sylvia encounters Keisha in the main story. She named her daughter after herself, something Sylvia would resent when she got older, demanding to be called Skip instead. After her mother's death, she goes back to Sylvia, and tells Keisha that she understood her mother so much more now that she was gone, and wishes she could tell her mother she understood her now.

In Part 2, Chapter 5: Taconic, it is revealed that, when they stopped at a Sunnaco station in East Fishkill, NY, Sylvia sees a Thistle Man attacking someone. Sylvia Sr. tells her to hide and gets out of the car to confront the attacker. The Thistle Man turns to see her, and attacks her, Sylvia screaming as her mother is attacked, and runs to try and help. An Oracle appears, and grabs Sylvia Sr. as she falls to the ground when the Thistle Man turns to get Sylvia. Sylvia Sr. looks into the darkness of the Oracle's hood, and sees something that surprises her, as the video from the surveillance camera, that Keisha and Sylvia later watch, records a rather surprised look on her face before she passes away.

Trivia

 * It can be assumed, due to recent incidents in the show, that the thing that Sylvia Sr. saw in the hood that shocked her so much was Sylvia herself, as Sylvia later goes on to become an Oracle.
 * It isn't known what exactly her job was, but it was one that required her to travel a lot.
 * She was a single mother, as Sylvia never talks about a father being around to Keisha, and, after her death, Sylvia says that she went to a few homes, presumably through foster care, before going out on her own.