"Oneechan" (お姉ちゃん) means "big sister" in Japanese and Ríona now understands that she is a big sister. Many things can be explained by this. Her ability to walk along the edge of a wall or to climb up something or to eat by herself are all because she is "Oneechan"
As usual though, she doesn't think this means what we think she thinks it means. Yesterday, watching Bambi, we got to the scene where he fights the dogs and saves his girlfriend. Ríona announced "お姉ちゃんですからね" - "that's because he's a big sister". Not much you can do but agree.