Hannah's character development in Yellow Jacket is actually so fascinating. Up until this point we've only really known her as a scared kid who sees things that she cannot explain. But in Yellow Jacket she's older, becoming more used to the things that make her weird. The visions aren't so terrifying as they are annoying.
Something I love about Hannah especially in Yellow Jacket, is that she is a little shit. She doesn't engage with Tom's attempt at bonding, she's short with Ethan's magic trick, she snaps at Webby. Yeah, teenagers are difficult but it specifically makes sense that she's become more difficult as she got older because look who raised her. The person she loves most in the entire world is Lex fucking Foster.
And once you realize that, it puts into perspective exactly why she takes all the actions she does.
Hannah sees the ring as a way to understand herself and as a means to help Lex. She throws herself into a stressful situation she isn't prepared for because Lex needs the money. She sacrifices her own safety because she can't come home to Lex empty handed. It's out of love, of course, but it's also what she was taught. And Yellow Jacket manages to illustrate this by having her decisions mirror the actions Lex takes in the same episode.
After Hannah's accident and the bill that came with it, Lex immediately jumps back into schoolwork, trying to pick up a second job and longer hours because she knows Hannah needs her to support them. In the very beginning of the episode she establishes (to us and to Ethan) just how stressful this is. Just how much she is struggling and how unprepared she feels. And later, when she does finally remember Hannah's birthday, she refuses to come home empty handed, racing back and forth across town to find anything that could work.
Yellow Jacket also establishes early on exactly Hannah's motives. Exactly what starts the domino effect of the rest of the story.
In the beginning of the episode, Hannah asks Webby if she can help their current situation, if she can help Lex. When she is told no, we see Hannah start to make decisions based on what is going to help her sister. Her birthday is spent focused on getting tickets for an IPad. Not for herself, but to sell. Her initial decision to go through with the fight, to push past Ethan's reluctance and her own nerves is because Lex needs the money. It's only after she wins that she feels that sense of belonging and companionship that makes her want to keep fighting.
Hannah was literally taught, by Lex, to prioritize her sister's happiness above everything else. Even when that comes at the cost of sacrificing yourself. Anything to make sure you don't go home empty-handed. Lex, while being difficult, is also very responsible. She will sacrifice so much for the people she loves without a second thought. Hence her throwing away her test on Hannah's birthday, and the reason why she leaves Ethan in the end.
Now, for the first time in her life, Hannah has friends. Friends who are in some massive trouble. Her sister taught her to fight and sacrifice for the people you care about. As such, this time, the danger is not going to deter her, not like it had in the past. No matter how much Webby pleads.
After all, Webby specifically told her she couldn't help.
And that was when Hannah figured out there was a way she could.
