Do you like shojo adventure stories? Are you up to date on Yona of the Dawn and seeking something else in a similar vein? This series is easily your best bet.
PRINCE FREYA (Itsuwari no Fureiya), by Keiko Ishihara. First published in 2017 and first published in North America in 2020.
PLOT:
Ever since her mother fell ill, Freya has depended upon the kindness of the village for their survival. They do this not only out of the kindness of their hearts, but also because Freya's eldest adoptive brother Aaron is a personal knight to Prince Edvard, and as such one of the few people keeping the invading forces of the kingdom of Sigurd at bay.
Then everything goes drastically wrong. Freya learns that the prince is dying of poison, and with his dying words he tasks her with taking his place. She manages to save Aaron from enemy forces, only to lose him shortly thereafter. Now she and her other adoptive brother, Alek, must grapple with their grief and guilt all while Freya learns how to act like a prince.