My husband and I have 5 children altogether just not with each other and I had to have my tube tired for medical reasons. My sister said that she will have a baby for me with my husband so we don’t have to go through all the fees for a segregate but my question is how do I go about adopting the baby and having my name on the birth certificate with my husband?

The same way you go through ANY legal adoption---with a lawyer, through the courts.