I love this one. It’s a Manhua called The a Epic Revenge.
http://www.mangago.zone/read-manga/the_epic_revenge/
Wait, the guy is a Marshall not an emperor, sorry. But it’s a great read.
I believe the name of it is "Mikado no Shihou" if I recall it correctly. I hope it's what you're looking for. Wonderful piece regardless of how young she looks.
Thank you! That's it!
I'll mark this one. Thanks for the recommendation
No worries, I’ve done the same thank you, yours looks interesting too. (▰˘◡˘▰)
The Epic Revenge is more cheeky but has a similar element where the girl is trained in medicine.
Little girl who is already an adult and saved a guy who turned out to be the emperor. Adopted by an old doctor of the village and became a doctor herself. Became friends with the emperor and fell in love with him