Hey, Lizzy!
Welcome to PA! I've read your app for Anna, and I like her. However, I'm thinking she's going to have some difficulties in either Slytherin or Ravenclaw--for a couple of reasons.
First, Slytherin is built on a foundation of not just tradition but also of the importance of pureblood purity. If she's a halfblood, she might have difficulty accepting the idea of pureblood superiority that the Slytherins believe so much in. I think she might accept the idea of the importance of tradition, as such, but since she's been raised in both worlds, she'd have far more tolerance of muggles, halfbloods, etc., than the average Slytherin. Thats a bit of an obstacle for her.
Second, as a Ravenclaw, one of the hallmarks of a Ravenclaw is not just their intelligence but their love of learning. Anna likes to learn, but she doesn't like to do all the work to get there. Not exactly holding with a Ravenclaw.
However, of the two, I think she's a better fit as a Ravenclaw rather than a Slytherin. Do you have a particular preference for her being a Slytherin? Or would you be okay with her being sorted into Ravenclaw?