Interesting take on the skirt frill, pippop1 - I have a few flippy / frill edged skirts from a couple of years ago that I find I just can't wear these days. I thought I had just got bored of them / I had moved to a more minimal style, but maybe they do just feel a bit young for me now (43).
Also on older women, I think flippy skirts can potentially look dated & aging rather than fresh - a bit "Twiggy at M&S". (I say 'can' because it's very personal & there will always be people of any age who can style it to suit them).
OTOH I think shorts as day wear (tweed & opaque wool tights) is perfectly acceptable, so what would I know
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Shorts as evening wear is beyond me though, unless you mean pyjamas.