Hi A.,
My daughter just got her ears pierced for her 6th birthday. I would highly recommend NOT getting them pierced with plastic earrings. My daughter used plastic and although the plastic is hypoallergenic, they are very porous, which can allow bacteria to grow. I didn't realize this at the time I got her ears done, and although she fortunately didn't get any bigtime infection, they didn't heal up the way I would've liked them to. I don't recommend the 14K gold either. 24K is pure gold, so the 14K are part gold and part something else (which can vary based on the color). Apparently white gold uses nickel as the alloy, which is very allergenic. I recommend titanium. It's very strong and pretty inexpensive and hardly anyone is allergic to it. Most of the piercing places these days recommend titanium. I'm pretty sure that most places have it. I know Claire's does.
Also, I recommend going early in the day and getting them done at the same time. I made the mistake of going in the evening and getting them one at a time. Oops! My daughter got the first one done and cried for nearly half an hour while I tried to convince her to do the other one. In the end, we went home with only one pierced and went back the next morning to get the other one done. She was much braver (having just had 10 hours of sleep!) and only cried out, OUCH! and was done with it! Timing is important when pain is involved.
Anyway, I know that wasn't your question, but I thought it might be helpful based on my very recent experience :)
Good luck!
J. B