Want some spoiler?
Read if you want
Rosetta is empathetic to Maxi. She does not particularly "not like" Maxi, rather she is understanding of her situation. All this time, since they were kids. Everytime the Duke punish Maxi on that room, he made Rosetta watch the whole process. Ingraining on Rosetta's mind what will happen if she also mess up. So in that way, she is also mentally unstable and abused. She likes Max but she's not very showy. I remember they will be an exact conversion between Maxi and Rosetta soon about this. Max will specifically ask her if she dislike her. Just wait for that chapter. I'm too lazy to go back to the novel and look it over.
Hope that helped
Yeah thanks for letting know it
I intrigued as to why the sister helped I though she didn’t like her? She was so mean to her in the chapter before Riftan came im wondering if she has another agenda? Mmmmmm