In a post-credits scene, Carina presented Sif and Volstagg to her father, the Collector, when they brought the Aether. When the Asgardians left the museum, Tivan revealed to her that its purpose is to get the six Infinity Stones.
Carina is first seen sitting down when The Collector threatens if she doesn't get to work, she'll end up with a similar fate to a past assistant to the Collector, who is in a cage.
She is later seen inviting Gamora to meet the Collector and overwatches as he explains to the Guardians about the Infinity Stones. She is tempted by the Orb and reaches for it claiming that she would no longer be the Collector's slave. She cannot handle the power of the Stone and is destroyed.
Thor: The Dark World
Guardians of the Galaxy