Even she wrote an emotional farewell on her Instagram.
"Hannah...I love you...and I let you go," she wrote.
However... while we're sure that Hannah's story has finished, Katherine has hope that she may still come back for a third season.
"I think that 13 Reasons Why, you know, even if Hannah isn’t in a season three, her story is something I’m gonna carry with me and I think also a lot of other people are gonna carry with them and I just hope that, if anything, I can be there in a small way on social media,: she told ET about her potentially joining the cast once more.
But she didn't end there!
"I mean, if they want me…that’s all up to them," she added.
"Hannah is… Hannah’s done, Hannah’s wrapped, I’m so glad I got to tell her story, it was really special."
Clearly Katherine would love to join the show again, and can you blame her? The show has been absolutely monumental in so many ways. However, it's important for the storyline to continue in a way that is helpful for people who are struggling. Not just drag something out that could potentially be hurtful for viewers.
So unless Hannah returning is essential for that, we don't see why the show creators would want to dredge up that painful storyline once more.
If you, or someone you know needs help, speak confidentially to a trained counsellor 24 hours a day:
Kids Helpline on 1800 55 1800.
Lifeline on 13 11 14
Beyond Blue on 1300 22 4636
