That speech from the sister actually changed my opinion of her. She’s a brat but she’s also a child with a terrible mother (and father) in a deeply patriarchal society that views women as objects to be bought, sold, and traded. She was always acting out and feeling like her sister got all the attention as the sick one. She’s been childish and a bully. Both of which, let’s be honest, are very typical of kids. I’ve worked with them and been one and they can be so cruel because their brains and empathy aren’t very developed. They’re selfish. But she also had no adults that discouraged bad behavior. Instead they encouraged it. And she’s going to married off as goods the same as Satako except she probably won’t have any say whereas the father, awful as he is, “let” Satako have a choice until he got fed up realizing she’s never going to settle and he can’t play good cop anymore to get his way while looking like a “kind father”. I can see how a little girl would see all of that and be bitter and jealous of how the world feels like it revolves around her sister despite the beliefs instilled in her by the patriarchy that she herself is “higher quality goods to be sold” vs her sick sister as “low quality goods” and that despite that nothing she can do will ever make her favored by others (which is because she had a terrible personality encouraged by her mother). I’m hoping that seeing her older sister like this will help open her eyes a bit and that we may see her allying herself with Satako in the inevitable conflict to come. She seems to understand what a callous family she is in and in this scenes seems to take delight in Satako finally having to face this reality that she herself has known all this time because she has not been fed delusions like Satako. I think she’s a little jealous that Satako has been sheltered from this reality and enjoyed seeing her be “torn down from her pedestal”. It’s sort of about how women all realize the deeper implications of their existence under a patriarchal world and get jealous of those who are living in ignorant bliss or have been sheltered from it. That seems to be a major reoccurring theme