The Queen writes in a journal, much to the concern of the Council, who worry about what she is writing about them. These journals are encrypted with protective spells so nobody other than the Queen can read them and she has told them this so they can stop worrying. They haven't. The Queen actually writes about how she feels her day went, what she enjoyed most and changes she'd like to see in the Kingdom she knows her people are not ready for as yet. She does not feel she needs to share that with the Council and indeed feels a certain amount of freedom in not doing so. She doesn't expect them to understand that (rightly) but Eileen does (she's the only other one who knows about the journals and has the encryption spells, after persuading her cousin it might be useful if someone could access her books in the event of an emergency. The Council do not know Eileen knows them.).
Eileen did kept a diary while in the Kingdom but this was literally a record of all she had done and had to do. She thinks what the Queen writes is trite (it is!) but can see this as a form of necessary self expression. Eileen finds her needs for that well satisfied in swearing at Brankaresh and the Council on a regular basis!