From Maid to Mother(2016)

Maid kara Haha ni Narimashita

A high school girl reincarnates in another world as Lily. While she occasionally reminisces about her past life, she is now known as "the Maid of the Royal Family," after helping to rear the lady who eventually married the crown prince. One day, the court magician Leonard suddenly requests that she acts as a mother for his adopted daughter Jill.