lady hogwarts, whilst very cool does add a huge dynamic to your story... both good and bad... how will she affect harry. should she not be able to control everything taht happens within hogwarts... why has no-one ever mentioned her before... why have there never before been any wards... over the years, has her control and power been suppressed. what is her original purpose (was she to be a guide for the headmasters/mistresses) was she to be a guide for her students... can she tell voldy is in 'her'. or can she feel darkness. does she consider darkness as evil?
like i said. lady hogwarts is very interesting, but this brings with it soo much more. not be mention the phoenix.
it was a gamble to introduce the castle as a sentient being, however she is a castle, she will have feelings of events but not be able to tell what exactly they are only a location. The subject of darkness is an interesting one that will be addressed as she was built in a time where the dark was a part of everyday life so will that effect her reactions i don't know yet, she won't become some sort of seer for harry, just a guiding figure. She has become diminished over time and this will show in later chapters.