What Bracha do you make on the birth of a child? What Bracha is made on a Boy? What Bracha on a Girl? When is this Bracha Made?
The gemara says that you can say Hatov vehameitiv when you have a son. It also says you can say that same bracha on any 'besorot tovot' (good tidings). Both of these rulings are quoted in the Shulchan Aruch (OC 222:1 and 223:1). In my experience, hearing about a daughter's birth is pretty top-quality good tidings.