Running an orphanage known as the "Sheep's House", her seemingly benevolent nature caused her to be known as the "Holy Mother". Notably, she took care of a young Charlotte Linlin, who would later go on to become the Yonko Big Mom.
~!Mother Carmel was a child trafficker dealing in orphans who operated in the Underworld several decades ago, under the code name "Mountain Witch". In reality, she sold her orphan wards to the World Government every two years to be trained as Marines or Cipher Pol agents, until she met her end 62 years ago.!~
(Source: One Piece Wiki)