Qurina was a cop on her home planet Calados in the middle of drug bust gone bad when a Green Lantern Ring found her. It welcomed her to the Green Lantern Corps, and then took over her body. The ring had been sent out by the Mad Guardian to Qurina and hundreds other, and transformed them into his private army. Like the rest of these mind controlled "newbies" Qurina killed several of her people, then flew to Oa where they fought the last remaining uncontrolled Green Lanterns, until the Mad Guardian's death, when they gained control back.
Major Story Arcs
War of the Green Lantern: Aftermath
For more information see War of the Green Lanterns: Aftermath
Qurina refuses to turn in her ring and seeks out the aide of John Stewart, for moral guidance. While talking to him she gets a distress call from her sector, and responds, with John in tow. A civil war has erupted on the planet Vorrin-Tog. John lets Qurina take the lead and she uses her ring to try to force the inhabitants to stop fighting but it escalates things.
John steps in and orders Qurina to makes sure the inhabitants don't kill each other while he speaks to there leaders. He brokers a peace and Qurina helps with the treaty. Qurina realizes she has a lot to learn, but knows John will always be there for her, and looks forward to training as a Green Lantern.
Later, Qurina is seen with dozens of other Lanterns responding to an evacuation of Planet Evarass-12.