In Calvinism, the children of believers are considered "members of the covenant" and as a sign of that covenant, they are baptized as infants.
Practically speaking, this means that if at least one parent is a Christian and member of the church, then the child may be baptized. But sometimes, people other than the parents might be considered "responsible" for that child's spiritual well-being, and thus a child could be baptized even if neither parent is a Christian/church member.
Sometimes those other people are grandparents, but the issue quickly gets tricky – for example, what about the cases of household slaves or foster children? Usually, the litmus test is that the "sponsors" of the child must be in a situation to train and nurture the child.
However, I recently saw the claim that John Calvin believed that descendants of Christians, even several generations removed, were entitled to the sign of the covenant, without the requirement of a Christian "sponsor." So, for example, the grandchild of a deceased member of the church would be entitled to infant baptism, even if no one else in the family is a Christian.
My initial reaction to this claim was skepticism, but on reflection I'm wondering if this would fit well within Calvin's system. Did Calvin believe that descendants of church members, even to two or more generations, were entitled to infant baptism, even without a Christian guardian? Where in his works does he argue for or against such a position?