Kusushi no Hakushaku Reijou wa Densetsu no Koryuu ni Aisareru

The earl's daughter Fiz inherited her mother-in-law's skills as a pharmacist, which were already becoming obsolete. One day, she found a baby dragon who lost its parents, and she secretly took care of it. She named it Kuel, who was the legendary Holy Dragon Rune Fairies Dragon and could manipulate various magics and even become a humanoid! Fiz tries to raise the beast even though she is unfamiliar with parenting, but due to the schemes of her sister-in-law and her fiancée, she is falsely accused of murdering her lord.

(Source: Kadokawa, translated)