My partner is a professional body piercer, he's been in the industry for about 17 years now and has put his foot down that our daughter will not be getting her ears or anything pierced until she is old enough to sign for herself which is 16, and it will be him or somebody that he recommends to do it.
Modifying the body of a minor without their consent is wrong. (religious/cultural views aside)
Piercing guns are extremely dangerous because it is a blunt object being rammed through your flesh. They cannot be properly sterilized, they would melt if ever put into an autoclave.
People who pierce with guns have not been properly trained, often times the holes are uneven. Most importantly, they have no clue about cross contamination and blood born patheogens. Hepatitis can live on a dry surface for AT LEAST 15 days, TB can live on a dry surface for AT LEAST 45 days.
Ok, I'm off my soapbox..
My mother took me to get my ears pierced when I was 5-ish, I remember it hurt and I didn't want the second one pierced, but the woman tricked me and quickly did the second one. I had infection after infection because of those butterfly backs they use because they can't be cleaned properly. At 12 I got a second set of holes pierced, the woman who pierced them was an old lady who is a hair dresser at the flea market... She "sterilized" her piercing gun with Windex, because "Windex kills bacteria and disease," but gave me a blank look when I asked her if Windex really does kill disease, then why don't they just inject people who are HIV positive with Windex, and then there wont be anymore HIV and AIDs. She put on a pair of gloves, then moved her hair out of her face and remembered that the cash register was open, so closed the drawer and pierced me before I could say I changed my mind. I regret not waiting until I was a bit older and able to go to a tattoo shop to get pierced properly by a professional.
Sorry for the novel.