Diondra is the worst girl ever with the "worst name ever" (14.33). She kills someone, has a baby, goes into hiding, and is eventually arrested. Good riddance.
Ben describes Diondra as "rich but sleazy" (4.6). Well, she's rich to him, but so is anyone with more than four bucks in their pocket. And sleazy is putting it mildly: Diondra is controlling, manipulative, violent, and flat-out insane. We don't understand how a girl like this could fly under the radar, but Libby doesn't remember her at all. "I pulled out the yearbook for the previous year, and she was gone. I pulled out the yearbook for the following year, and she was gone" (14.34). So where did she go?
First, we have to go back to the beginning. Diondra meets Ben when she literally hits him with her car… and then they make out. Ben likes the attention. Diondra… we don't know what she likes other than being terrible. She buys Ben clothes, yes, but only so she can make him into whatever she wants him to be. That's not actually very generous, is it?
She soon gets pregnant, and she takes advantage of Ben because she wants to run away from home. Ben wants to be a "useful man" (4.7) and Diondra uses that to manipulate him. She wants him to steal money from his family—a family that has no money—and move to a different city. Yeah, that's going to work.
All along the way, Diondra makes fun of Ben, and, with her friend Trey, the three of them engage in bizarre Satanic behavior—you know, things like sacrificing a cow and leaving animal organs in Ben's locker (which he doesn't clean out, for some reason). Is she just spoiled and bored, or is she evil on the inside?
We're leaning toward evil. When Ben's little sister, Michelle, finds out that Diondra is preggers, Diondra strangles her. Yikes. When they find out the rest of the family has been killed, Diondra sees this as a positive thing: it's an opportunity for a cover-up. What is wrong with this young woman? Could she have actually sold her soul to Satan? Because if souls exist, she doesn't seem to have one.