I was married when I gave birth to all three of my kids.I have since gotten divorced and DNA proved my husband was the bio father of one child no one is on any of the birth certificate. I'm getting remarried soon and my new husband would like to adopt all three kids how do I do that... also I don't know who the bio father would be

If you live in the US (laws differ in other places) if you were married, reqardless of birth certificate, the husband is always considered the legal father. The rules to contest this is different in each state. So your ex husband is still the legal father.

This can become complicated, and expensive. The ex husband can deny being the father (in many US states) and ask for DNA test. Then you will have to attempt to find, according to court rules the real bio father.

You will need an attorney, who is very good at adoption issues for your state. (if you are in the US)

As noted any question on law needs to include your general locale as laws vary by area.

But in all of the US your ex husband is the legal father of your children. Every state has a law that states that when a child is born to a married couple the husband is the presumed father. In fact, I am wondering how you got birth certificates with no father unless you lied to the hospital and told them you were not married. If you told them you were married they should have put your husband on the birth certificate.

Again, subject to local laws, it is probable the adoption court will require that the bio father be identified and give his consent to the adoption. Do you if your ex husband will consent? If he will, the easiest would be to to acknowledge him as the legal father and have him consent to the adoption. If he won't consent then you will have an uphill battle. Since he can probably enforce his legal paternity, he could, very likely, block any attempt for your new husband to adopt.

If you ex will not assume legal responsibility for any of the children, except the one DNA proved was his, then the court will probably require that you contact the potential fathers, and have paternity established so they can consent to the adoption (or, at least, make a good faith attempt to contact them).

Bottom line; you need to contact a Family Law attorney to prepare the adoption petition for you. You have made this a complicated situation that needs an attorney to unravel.

Besides the issue of why the ex-husband isn't on the birth certificates, I wonder why the issue of paternity wasn't considered in the divorce. Normally, the paperwork to be filed would ask if there are any children, etc., and child support would have been ordered and custody/ visitation considered for all children of the marriage.