Status Updates From Criminal by Terra Elan McVo...

Nikki’s life is far from perfect, but at least she has Dee. Her friends tell her that Dee is no good, but Nikki can’t imagine herself without him. He’s hot, he’s dangerous, he has her initials tattooed over his heart, and she loves him more than anything. There’s nothing Nikki wouldn’t do for Dee. Absolutely nothing.

Nikki is a vulnerable and conflicted teen who craves love and stability more than anything else.
She becomes intensely attached to her boyfriend Dee, believing that his affection gives her life meaning.Nikki’s loyalty to Dee leads her to ignore red flags and make dangerous choices to keep him happy.As the story progresses, she struggles to understand how her devotion has trapped her in a life-changing crime.

Nikki's main conflict is that she is feeling shame and guilt for helping Dee kill someone. She now realizes that she did all of this for someone who didn't even care about her, and now she has lost everyone who cared about her. She feels like she has lost her entire life by being stuck in jail for someone who wasn't worth all the pain and trouble.

I would use Ariana Greenblatt because she is a younger actress and I think she would be able to portray the emotions that Nikki feels in the book.