The Wicked Little Princess summary:
As the one and only fire witch in 300 years, Liona spends her life isolated from the world... until she falls for Rakus, prince of the Kingdom of Carrell. But after he betrays and kills her, she opens her eyes as the newborn baby princess of the Hasys Empire! With her OP-level strength and royal dragon-blood lineage, she’s out for revenge against Rakus. To get there, she must first secretly harness her mana, find people she can trust, and defeat her 11 siblings to gain the power of the throne!