I tend to not be in favor of piercing babies' ears. Of course, I wanted mine done as a girl, but I wanted lots of things that my parents had to say no to. It was a rite of passage for me to have my ears pierced as I was graduating from fifth grade. It wasn't at all unpleasant, but I remember the experience and was never interested in piercing anything else. (That's something to think about, huh?)
I don't mean to make it bigger than it is, but I think of it in terms of something to look forward to. Kids are getting so many things earlier and earlier in life that they have little to aspire to, and they perpetually seek all kinds of new heights. They develop a sense of entitlement and rights to things just because they're here and/or because every other kid has it or is doing it. We are to blame for our current "microwave" era, the age of instant gratification. Making me wait for earrings--for the permanent holes that are in my earlobes and the jewelry pieces that go with them--helped me not to get ahead of myself and to teach me the responsibility of maintaining my earrings and ear health at an age when I could really appreciate it. (I learned to keep up with my earrings because I was old enough to be disappointed when I'd lose one.) I don't think that it's necessarily a good thing to pierce a baby's ears before she understands how to appreciate it, when she can just grow up already used to it. It's like the concept of allowing a child to have a pet (any kind), something to take care of, to be responsibile for. There are basic life lessons in these simple things that children miss out on when we don't allow them to grow into certain privileges, to learn how to wait and earn something, to feel that sense of accomplishment instead of a lifetime sense of entitlement, or even a sense fo failure because they haven't been taught how to work/wait for something.
Now, that said, if you still choose to have this done, it would be a good idea to just keep this other stuff in mind so you can instill these values/lessons in other ways.
Enjoy your daughter and take good care!