13yo DD's school has sports' week. As the weather is warm (SE England), she's been wearing shorts to school. This morning DH (her dad) had a go at her for wearing it 'all week' and how short they are- she has 2 pirs, so not been wearing same. I normally berate my DD for wearing her school skirt too short, but this time had to defend her. Yes, the cycling-style cotton shorts ride-up a bit, but I see every other young girl having the same 'problem'. DD had skort, but she hates it and I don't think it's good in this weather as it is synthetic.
AIBU to think it's not 100% ok, but there is no alternative and she can walk to school in 'short' shorts. The shorts come to maybe 1/3 of her thighs.