I feel like this princess is a transmigrator but she got a bad personality even though she transmigrated into a main character in a novel the only difference is that Philomel the villainess became the mc🐤maybe like from G**'s perspective this princess may do something that may caused a huge problem in the future which could ruin their world n decided to let Philomel who was supposed to be villainess see her own fate/future through the book/novel.
She's the author of the book philo read when she was younger so yes she technically did transmigrate into a book but it wasn't hers rather philos she thought everything would still go according to the book she wrote
@Kaiili yeah now I understand and maybe the G** from Philomel's world showed the book for our mc so she could be prepared for some unfavorable circumstances in the future due to blondie