Black Belly Enchantress (old version)

[The cover used is not my own artwork ^^] She was originally known as the genius doctor of one of the famous hospitals in the 21st century. But this "genius doctor" title was just used to conceal her true identity as the most respected agent of a secret organization. In the middle of her team's mission, she unexpectedly fainted and the moment she opened her eyes again... she discovered that she was transported into another world where mystical things existed. The previously 26-year-old genius now possesses the body of a 12-year-old young miss of the Bonneville family. Perfect body and appearance. After realizing that she is now a great beauty, she's naturally happy about it but... she's also aware that beauty could also bring disasters! She could only do her best to get stronger and survive in this mystical world!