If she was married to someone else when the child was born, the child is legally considered her husband's child. The Husband has full rights, and you have none until you do something legally. You will need to file a Paternity case to get DNA testing to prove that it is your child, and then you can seek legal rights through that case. These types of matters can be very complicated, especially if your ex or her husband are going to fight you. Thus, you would do well to hire an attorney to get you through the system.
Responses are for general information purposes only, and are based on the extremely limited facts given. A consultation with an attorney experienced in the area of law(s) indicated in the question is highly recommended. Information and advice given here should not be relied upon for any final action or decision, as the information is limited by its nature to the question asked and the fact(s) presented in that question. THIS RESPONSE DOES NOT CREATE AN ATTORNEY/CLIENT RELATIONSHIP, particularly considering that the names of the parties are unknown.
Ms. Whitbeck is spot on. I suggest you seek a consultation with an experienced custody attorney in order to more fully explore the particular facts of your matter and get you pointed in the right direction. Good luck!
Ms. Whitbeck is correct. Even if your ex was not living with nor returned to her husband, the law is often blind to practical realities. You will have to file to establish paternity. Realize too, that once done, there's no going back. You will be on the hook for this child, visitation or not, until the child turns 18.
Sign up to receive a 3-part series of useful information and advice about child custody law.