Outside reading: Bound

I realized when I was reading the story that it's actually a retelling of Cinderella. My book is about a girl who lives in China with her step mother and step sister, her step mother has bound her step sister's feet so that she will be married, while the main character must work and serve her family. Throughout the story so far it describes her as very pretty, but because her step mother doesn't like her she must work and clean all the time, which sounds a lot like Cinderella to me. And also there is supposed to be a huge party comming up in honor of the new emporer so I think I have an idea of what's going to happen.

I have began to wonder why Xing Xing's (main character) step mother doesn't like her. I'm not sure if it's because she's prettier than Wei Ping (Xing Xing's step sister) and is jealous, or if it's because of something  Xing Xing has done in the past. But I don't really understand why she would hate her so much because Xing Xing is very obediant and does everything that her step mother asks of her.

I'm surprised with my book because Wei Ping has become ill, and Xing Xing's step mother has sent her off to find a doctor in the city. Which is surprising because this whole time I've been thinking it's a retelling of Cinderella . But in Cinderella she wouldn't have let Cinderella leave at all. So I'm surprised that this isn't exactly the same because throughout most of the book it's been the same. Now I'm begining to doubt my hypothesis that this is a Chinese retelling of Cinderella.