When visiting churches all adult size people - both male and female (kids under 10 or so are exempte

HI. Visiting Italy during June and July when it is likely to be hot. I have a teen daughter and just want to check what is acceptable attire. I have heard knees must be covered when visiting churches. Is is acceptable to wear leggings with an above the knee skirt or must the actual skirt be below the knees. And when not visiting churches, is it accpetable for teens to wear slightly shorter skirts or shorts?Thanks
When visiting churches all adult size people - both male and female (kids under 10 or so are exempted) must wear clothing that cover the knees, the shoulders, upper arms and bosom (many sundresses 4 star florence hotels would be unacceptable).
This is strictly enforced at the Vatican (if you don;t qualify the Swiss Guard will turn you away) and also pretty well at major cathedrals - but unacceptable dress is likely to be pointed out by locals (usually elderly ladies) in any church - which is not something you want to be the object of. (I was in a smaller 4 star florence hotels church in Rome and a scantily clad young woman - shorts and tank top - came in - and a local shooed her out - accusing her of being a member of the world's oldest profession (putana).
Thanks for the advice. Suze, you know typical teenager, they like to have their style, but i will definitely let her know heat will be an issue and encourage her to get a longer skirt for those church visits.