She didn't answer right away, clearly thinking about her answer. Why, though, Neil couldn't exactly guess. Eventually, she told him, "Right after it was confirmed you were a legitimate alicorn, the entirety of the senior castle staff, the infirmary staff, and the castle garrison were informed of your existence yesterday morning. The Princesses know as well, obviously. The only other ponies that know of your existence would be the three city guards mentioned in the report. And having been sworn to secrecy, I can only deduce that those three guards were also sworn to silence by the Princesses."