Eugene offered her a bow,
"Thank you, milady. I shall drink it later." The vampiress obviously meant no harm and was only trying to be appreciative and he didn't see a reason to be mean towards her by refusing it.
"Of course!" Rosetta was glad to hear anything Eugene said, and then she realised the milk wouldn't be warm later. But maybe, he preferred it that way? She observed the room and said, "These rooms don't have windows or balconies."
"It seems it was once used as a storage room, which is why there was no need for a window. But in time, it was changed to rooms for the guests to be used. By vampires who prefer their quiet isolation," Eugene explained to her, and Rosetta nodded. She also realised the only light that came into the room was from the candle that Eugene held in his hand, and the room's main door through which she had entered.