I personally wouldn't want to make such a decision for my child, even though it only seems to be a minor thing. I had my ears pierced when I was around 8, and I had saved up my pocket money to have it done. My sister was older than I was, she was maybe ten. I'm glad my mum gave me the choice - she couldn't know beforehand if I wanted them or not.
Also, I did grow and my earrings got off-centered. (And as I said, I was 8, not exactly a baby!) One was 4 mm lower than the other. I've also had my earring ripped out 2 or 3 times, because the hole was so low. To fix this, I had to stop wearing earrings for about a year (I did this when I was around 15, because I couldn't wear any earrings anymore because it looked so stupid) then have one pierced half a cm above the original hole. The original hole is closed up now, but I'm still too afraid to wear any kind of heavy jewelry in case they will rip out.
Usually, I do not wear earrings, only occasionally, a couple of times every year. Most of the time I do have two quite visible scars. It was my own choice and I don't mind these scars..but what if your daughter grows up hating them?
"By God," says he, "I think the Devil shits Dutchmen."