When we were kids my sister wanted her ears pierced, so my Mum made her wait until her 10th Birthday as she was deemed to be old enough to safely look after them / keep them clean to avoid infection etc!
This did however lead to quite an amusing conversation between her and an elderly lady in the village, where the lady asked what she got for her 10th Birthday, to which the angelic 10 year old replied “I got my ears pierced and a shotgun” (my Dad had the same attitude towards shotguns as my Mum did pierced ears)!