To tell the truth, Enisphia and the others had not thought about this question before, but now that it had come up, they were indeed very curious.
The reason was simple.
Enisphia was a Princess. Even though she had voluntarily given up her right to the throne, she was still a Princess. Yuriya was a Duke's daughter and the fiancée of Prince Highness, the future Queen Consort. Teerdi was also a Duke's daughter. With the three high-born ladies coming together, it was certain that they wouldn't be subjected to sleeping on the ground.
But military campaigns are quite different from leisurely outings, and there are many inconveniences for girls, after all. Thus, they were provided with a relatively luxurious large tent. Of course, being on a military campaign, it's not possible to bring a palace over for them, but the three of them were living quite comfortably.
