I think the two of them are so cute together! She needs to let go of the story and realize her feelings for him (it’s already changed because of her attitude towards him anyways)
Incest is a big no-no for me and I’m pretty careful about it. Even if two aren’t blood related, but grew up thinking of each other as siblings and suddenly change, then it’s gross. In this case, she only treated elios as a little brother so she doesn’t die and elios clearly never thought of her as a sister. That’s why I think this story’s in the clear and I enjoy their romance ☺️