I have two children that is 19yrs old and married I have is going to be 18yrs old and has has a baby should that stop payment to them

Possibly. What does the child support order say regarding when CS need not be paid any more? Often it's only payable until the child is 18.

Being married may emancipate the one child freeing you from support. But having their own child won't emancipate the other. If they are still living with the custodial parent, they still get support.