Nail varnish sometimes for fun when she goes to her aunt's (sil has all those picture painting varnish brushes). Jewellery - just play stuff (plastic baubles and lurid pink Barbie bangle type stuff) and only if its a "play" setting (GPs house, home, popping out to the supermarket...). She's 5.
"Real" varnish and jewellery, hmmm, hadn't thought really, guess I'll play it by ear.
My 6yo wears age appropriate necklaces and bracelets occasionally. I feel it teaches her a good lesson in taking care of delicate things, it makes her happy and looks cute.
Where I live, ALL the girls wear nail varnish and most girls wear earrings. I think nail varnish is awful on children, mainly because it wrecks their nails. My kids haven't really asked for nail varnish but I would discourage it.
I've said to my older daughter (8) if she really wants her ears pierced, she can. She said she wanted them done but hasn't pushed the issue, so I'm leaving it until she really wants them and isn't just wanting what her friend has.
DD is 7. She occasionally wears nail varnish on fingers and toes, but only in school hols, when she has seen her auntie who paints them for her. She wears a watch to school.
She has lots of plastic 'jewellery' which she wears when dressing up round the house.
She was a bridesmaid a year ago, when 6 1/2. She was given a lovely silver necklace by the bride to wear on the day, and we bought her a silver bangle at the same time, with money she had been given as a birth present expressly for the purpose of buying a piece of jewellery with when she was old enough. This proper stuff was worn on the day of being a bridesmaid, and Christmas day only. She is too active and clumsy for it to be worn frequently, and I wouldn't want her to. Both necklace and bracelet should be suitable for her until in her late teens.
DD (5.10) likes to put nail varnish on me (oh somebody save me) and quite likes wearing it herself. I don't have anyproblems with it during the holidays, but not during termtime. FWIW she usually wears a silver one (I only own silver and black, I don't wear it that often myself)
Only jewellery she wears is children's stuff, although she's got 'proper' jewellery (presents) she's only likely to wear it if we got out somewhere nice (wedding, meal out) The rest of the time it's kept somewhere safe. Ridiculously my MIL bought her diamond/white gold stud earrings for her christening. She still doesn't have her ears pierced! Maybe when she's older... (they're very nice, but I'm resisting the urge to borrow them!)