Who is Chao Lingshen???

Its said she is a decendant of Negis but in UQ Holder it is reveled that Negi is sterile from his magia erebea transformation.. His grandchildren Touta and Cutless are both clones and Touta goes through almost the exact transformation Negi does so im guessing he is sterile too. Cutlass is evil and serves Negi as the Mage of the Begining so I doubt she has Chao as a daughter.... Who do you think Chao is? a great grandaughter of a one of the clones or a clone herself?