No! Just no!
Sienna wouldn't do that, she had a messed up relationship with her father, but she loved him and her relationship with Nico is nowhere near as strong as her relationship with her father, she would want justice for Patrick.
Good scene with Patrick and Sienna at the end, but it's not good enough to show Sienna's mental problems but not show her getting treatment.
This better not be a exit for Sienna!! I don't want to see Sienna/Anna leave, but if she has to go it shouldn't be defending Nico!