I still struggle to understand why Abby would go looking for Fireflies

If I wanted to try my hardest I could possibly believe that Abby is doing it "for Owen".. but that still doesn't quite cover all the bases.

Abby just got done with beating the sh*t out of Ellie and leaving her traumatized twice over. Even gave her a good ol, "Never let me see you again". IMMEDIATELY after they're looking for Fireflies?

Uhh. Hello? I thought Ellie was the only person capable of providing a cure? Do they not need her? Does Abby expect or want to see her again?