From a Leader to a fighter (Lexa x Oc)

Question

So I have decided that Rocky will go into the bunker with Octavia. In order for the storyline to flow perfectly Lexa has to die...

I'm just kidding. Don't take this book out of your library yet. I don't know how to fit Lexa into the book so she will get kidnapped and Rocky will believe she died. It'll make since when the time it right. I'm putting this spoiler here because I won't tell anyone that she is kidnapped until later on. So the people who skip this chapter will think she died. 

Anyways the question that I have is about Isabelle. Should she go into the bunker with Rocky to help keep her sane or should she stay on the earth with Clarke, Madi, and Lexa since she has night blood.