We went through a similar situation, with some differences. At first, my husband wanted a baby much faster after our first than I did. Then one day he just sprung it on me that he thought he did not want any more. I accepted his decision, because my son is such a great part of our lives that I figured my life would still be complete without another baby.
Then I got pregnant unexpectedly, and miscarried. We didn't know for sure about the miscarriage for a few days, so we had some time that I thought there was a good chance that we were expecting a baby that my husband did not want. He surprised me, by being happy about the pregnancy. He was equally as devastated as I was when the pregnancy ended. It put things in perspective for him. Now his view is that we could be genuinely happy if our son is an only child, but if I get pregnant, he'll be equally happy. Strangely, now I'm the one that doesn't really know if I want another baby. But, I know if I get pregnant, I'll be happy anyway.
You might ask your husband why it is that he does not want another baby. In our case, my husband was concerned about finance, mostly. Once you know why he does not want another baby, you might be able to help him see that his concerns have solutions you can both be happy with. And you might be surprised to find out that his reasons make sense, and decide that one child might be a good idea after all.
In the end, it's more important that you both are happy with the choice. In the meantime, rejoice in the fact that your life has been blessed with a healthy beautiful daughter to share your lives with. I found myself reminding myself that so many people are not as blessed to have even one child, so I knew that my life was already so much more complete than so many women that long for a child.