In Final Fantasy Advent Children who is mother?

JENOVA, is the mother. It a alien and powerful creature from another world arrived to the planet and has the abilities to change from one sex to the other. Also, it is actually a crab. Although it is called mother, it is only mother to some of SOLDIER's finest (Sephiroth, Angeal, Cloud and ect.) And also mother to others who her/his/it's cells have been infused with. So if you hear mother, they are referring to JENOVA.