In my opinion, I don't think Kanade realizes the full extent of her feelings for Nanaki.
Unlike a few people, I don't believe she was "shipping" Nanaki and Izumi because she saw herself as unworthy. I think she just did it because of her princess obsession and saw Izumi as the perfect fit for the princess.
Not only that, but all the inner monologue that's shown makes it seem that she isn't aware of how she feels towards Nanaki. She might know that what she feels towards her is different than other friends, but she could easily just put that off as her obsession of princesses.
My overall point is that Kanade has more of grasp with her feelings for Nanaki, but she doesn't actually know what they are as of now. For example, while on her date with Akio, it appears that she remembers her date with Nanaki, but she seems a bit surprised and confused on why she was thinking about it. Also, her inferiority complex would probably make her reject the idea of having a crush on Nanaki.
There are multiple ways to interpret this situation though, so to each their own.