Diana went with Caine, Drake and Jack to Perdido Beach. She's one of the first to find out that Sam and Caine are twins. When Sam, Astrid and Little Pete are captured by Drake Merwin, she reads Astrid as barely a two bar.
Diana, Drake, Computer Jack, and Caine film Andrew taking 'the Poof' and are the first to discover the tempter. Before the Thanksgiving Battle, she sends Jack to go tell Sam about how to avoid the Poof, because she knows if Sam takes the Poof and leaves her with Drake, he will take out his hate on her, and she will eventually be killed. Her role in the battle itself is minor as her power doesn't really help her fight. Jack arrives too late, but Sam and Caine don't take the Poof, which allows her temporary fear of Drake to subside. After the fight, Astrid suggested her to join "Sam's side" but she refuses saying the bad girl always goes with the bad guy (Caine). It is hinted Diana has affection toward Caine, yet doesn't seem to express it or any other emotion. Also, she tends to act emotion-less always ending up sounding heartless.
Her and Caine had a romantic relationship. Caine was in love with her, and the feelings were presumably returned. Diana was the only one capable of standing up to Caine; she called him out when she felt he went too far, and hers was the only opinion he really cared about. He is also the father of her child Gaia, who has the power to grow or ungrow any age she pleases.
Diana did not like Penny, finding her creepy. However, despite this, she still cared for Penny when her legs were broken, bringing her food and DVDs, along with helping her get into the bathtub.
Diana has a power, although it was considered weak by FAYZ standards. She is able to see how powerful someone else is- they use a system of bars, with one bar being the weakest, and four bars the strongest. The only two four bars are Sam Temple and Caine Soren. However, Little Pete was by far the strongest mutant. He was not read- but they estimated him to be somewhere around a ten bar.
Two days after conception, Gaia was already a two-bar, which worried Diana. Gaia is one of the most powerful entities in the FAYZ, along with Little Pete.
Early on, Diana used her power to test the threat that others posed. Most people were two or three bar, and Caine was the only four bar until she met Sam..
"Time to do the right thing. Even if it's for the wrong reason." - Diana (Gone)
"Bada bum bada bum bada bum bum bum." - Diana humming the William Tell Overture (Gone)
"Sadism. Enjoyment of another person's pain." - Diana "Words don't scare me." - Drake "You wouldn't be a psychopath if they did, Drake." - Diana (Gone)
"Oh, look, Drake's trying to think!" - Diana (Hunger)
"We're sitting in the dark, willing to sell our souls for another peppermint, with enough uranium to give a terrorist a wet dream." - Diana (Hunger)
"No, you sick stupid creep, I love you. I shouldn't. I shouldn't. You're sick inside, Caine, sick! But I love you." - Diana to Caine (Lies)
"Betray you? I've been with you every day, every hour, from the start of this nightmare!" - Diana (Lies)