I think that there can be many, this is from Ultimania-Originally Posted by GunbladeMaster
....However, there are also many Sorceresses who have chosen to live a quiet life sheltered away from civilized society; as such, the actual number of Sorceresses and the amount of power shared between them remains unknown.
The potential to become a sorceress is determined by one's capacity to wield such power – their natural affinity for magic....
That last part would make Selphie a definite canidate.
