Folks do your research. Snow White Rose Red is a completely different fairytale. If Disney was doing this it was typical movie studio fashion where they just act like things are related that are not. Snow White is the name of two different characters in two different fairy tales. It's kind of like just because two movies have a main character named Jessica doesn't mean it's the same Jessica.

Granted, I seen no reason Disney would not have done that, but the way you wrote the story, you said Snow White indeed has a sister named Rose Red. In the story of Snow White where she is a princess with an evil queen stepmother, and there are seven dwarfs... she does not have a sister named Rose Red. It's a completely different story.