Do the children have to be present in order for the parents to get a visa

Two of our children have had Chinese visas in the past. Our infant has not. Does the two older children need to go with us to the embassy to get a visa? We will be taking the infant with us of course. The two older kids do not want to go and I am not sure if they must be there or if the parents can handle the papers without them being present. Thank you for your help in this matter.