If Lisa is already baroness, it means she already inherited the title from her father/mother. Either her parents are dead or stepped aside otherwise. Although that being said, I do recall them appearing in her talks with the prince, when the prince postponed talking about their engagement (which obviously is never going to happen). I reckon the author is just confused, like usual. This is the kind of author who can't really write a coherent story, which is why this series is just a pool of tropes.