Yakonjaga Jakkuman Nareul Kiuryeo Handa

After a lifetime of being treated like an outsider, former knight and princess Annette Hayworth is sent into a political marriage to Grand Duke Cardin Harzent, a man said to resemble a hideous monster. But when her carriage is attacked on her way to the empire, she finds herself turned into a child. Instead of fear and rejection, Annette is now surrounded by people who accept her as she is, including the grand duke, who seems to be completely obsessed with her. Why is everyone doting on her, and will she be able to get back to her adult self? (Source: WEBTOON)