Akuyaku Reijou no Yakuwari wa Oemashita

In exchange for God saving her younger sister’s life, Lefina is reborn in another world as a villainess. After giving a brilliant performance as the despised duchess, and ensuring that the heroine and Crown Prince are engaged, Lefina quit being a noble. Now, she works as a castle maid! What awaits her is a carefree lifestyle where she can eat delicious Japanese commoner food! She enjoys her new life while using her special skill that allows her to master anything with just one glance. Lefina enjoys the life of a commoner, and soon her reputation among those around her begins to change......? The happy commoner life of the former villainess begins here!

(Source: Alpha Manga)

Note: Includes 1 extra cha...