I absolutely had no preference. My first child is a son, adopted from infancy, but for reasons that had nothing to do with any fertility problems that I was aware of. So, I had the one son and was absolutely, absolutely, in love with him. When the time came for me to have another child I would have been absolutely thrilled to have "another one just like him". Then, again, I would have been happy to add a girl, since I had one son.
Things turned a little more serious when my first pregnancy ended at 20 weeks. I still would have been absolutely happy to have another one just like him, but what got added was the primary thought of having one make it to a healthy delivery.
My second pregancy resulted in another sweetie-son whom I absolutely, absolutely, adored and enjoyed; and I was really happy to have my little "set of boys".
By the time the third child was on the way, I'd become so used to having my little sons that I kind of wondered if it might be weird to have a girl. My daughter was born, and I discovered that having a girl wasn't a lot different than having boys (except for the pink and light purple that hadn't until then been too present in my home).
They were all unique in their own ways, but they were also all the same in so many ways. I vowed to raise each, from the start, as "human beings first" (and then let their sex take care of itself, once they got to the age when Nature started to make more distinctions).
So, my first child didn't happen to be my first-born, and my "first-born" happened to be a son. It was all good. I didn't make a big thing out their sex and still don't. They're individual human beings, and I still absolutely, absolutely, adore each of them. :)