Joou-sama no Inu, Kamisama Hajimemashita Recommendations
Both involve the growth of a romantic relationship between the strong female protagonist and her supernatural servant. Kamisama is a bit more light-hearted and current than Her Majesty; but if you liked one I would consider looking into the other.
Both girls have a high position and helpers (dog/familiar) which are at the same time their love interest. Both see supernatural things.