What happened that you didn’t know you have a daughter? Someone didn’t tell you they were pregnant? How old is your child? What are your plans now?

I disagree with others that your wife is being selfish or has no reason to be upset.

If she wanted man with kids, she’d marry a man with kids. She married someone without kids so why does she need to accept that it turned out not to be the case. Saying that it’s your right to end your marriage if she doesn’t accept your child. Neither one of you is selfish. Circumstances change and now you two have to make a decision what you are going to do now.