Jussai no Saikyou Madoushi

Ten-year-old Ferris is a slave working in a mine for magic crystals. One day, mysterious magicians attacked and destroyed the mine, and Ferris is the sole survivor. While fleeing, she impulsively rescues a beautiful girl named Alicia who was about to be kidnapped by suspicious men. As thanks, Ferris is invited to Alicia's mansion, where her magical talent is discovered— A heartwarming magic academy story about a ten-year-old girl with the brightest smile and strongest magic!

(Source: Hero Comics, translated)