If i remember mahabharta correctly Lord Krishna was cursed by Gandhari that as Krishna was instrumental in the killing of 100 sons he would die childless and hence how could he have any chldren. as far as I remember Lord Krishna did not have any child. he had 16109 wives of mor ( as per wikipedia ) but i am sure he did not have any children.
Secondaly Lord Krishna Mortal Body was cremated by Arjuna and last rites performed by Arjuna If Lord Krishna had 80 children why Arjuna performed the last rites of Lor krishna mortal Boday
Joyesh, would love to hear from you whether my contention is right or not ????