The Earthseed family keeps on growin'.
Emery and her daughter Tori are two people who come to Lauren's group while pretty much everyone is sleeping during a nearby gun battle. They're "the most racially mixed" (23.86) individuals Lauren has ever met: Emery had "a Japanese father, a Black mother, and a Mexican husband" (23.86). She's twenty-three, and her daughter is nine.
What's their background? In short, Emery worked as a debt slave for an agribusiness conglomerate, and her sons were taken away by the firm. When she protested this, she was given a drug to "quiet her down." Eventually she escaped with her daughter, and after lots of trouble, they encountered Lauren's group (23.86-98).
So Emery and Tori are basically some more hard-off, poor, ethnically mixed individuals who join up with Earthseed—what makes them special or unique, and why are they important in this novel? One thing that stands out about them is that their life experience with the agribusiness conglomerate suggests what might have happened to Lauren had she followed the Garfields to Olivar. In other words, Lauren would probably have become a debt slave.
Luckily, Emery gets away from the debt slavery and lives to tell Harry about it when he's considering finding paid work instead of staying on Bankole's land. Emery tells him (25.52-60) that the types of places where he might find paid work are the sorts of places where he might be expected to work as a slave-driver, something he turns away from in horror.
Not surprisingly, like many people in this novel, Emery is driven to survive and to take care of her kid, Tori. And there's one more fact about Emery: she's a sharer. Like Lauren, she has hyperempathy syndrome (24.48-51). This plays out more in Parable of the Talents, the sequel to this novel, which you should totally read.