Spending ten hours on the road, Princess Ievna forced herself to stay alert while on the carriage. Even if she felt tired during the long journey, she could not let her guard down when she was alone with the Crown Prince.
It wasn't that she was worried that the Crown Prince would 'attack' her or do bad things to her if she let her guard down, but she was worried that the Crown Prince would end up touching her even if it wasn't for bad intentions. One touch, and it was enough to bring her another nightmare.
Therefore, Princess Ievna kept her eyes open throughout the journey. Even if she was cursed to become a red rose fourteen years ago, she would still be able to sleep in her human form. She would also be able to feel tired in her body even if it wouldn't be as bad as when she was still a normal human, but she would still feel discomfort in her body when she was exhausted. However, she hid her tiredness because she was worried.