I have 3 daughters, 1 almost 17 (July), one 10, and one 9. All 3 of my girls have their ears pierced. We took the same approach that 12X took. We waited until they were old enough to know what piercings were and old enough to take care of them themselves. We allowed them to have their ears pierced on their 6th birthdays. All three of them loved the idea, and it made them feel like "big girls" to be able to choose to have them or not. They of course could hardly wait until their 6th birthdays.
When my oldest was around 13 she started asking for a naval piercing. I of course denied that straight away for the time. I did tell her that if she kept her grades up in school and kept a good attitude that I would consider letting her get her naval pierced when she turned 15. Well, long story short, she made A's and B's in all her classes, and the majority of her classe were AP or advanced classes. She also almost always dislayed a wonderful attitude. So, of course the day she turned 15 I kept my word and I took her to the piercing shop myself and let her get her naval pierced.
Since that time, she has asked me hundreds of times if she could get a very small piercing in her nose, or a tattoo on her ankle. My answer has been and always will be "When you turn 18 AND move out of my house you can do anything you want to your body, however UNTIL you are 18 AND move out you will live by my rules and you will have neither". She said ok, so I can get one when I turn 18, I said Sure, as long as you arent living in my house. But Dad, thats not fair..... Baby girl, Life isnt fair.
JaF