Would you wear leggings when you're presenting at a conference?
One of my junior lab mates is presenting her first paper at a conference. She's a broke PhD student with no budget to buy "fancy" clothes. She ran her wardrobe by me, asking if her plain black (non see-through) leggings would do. My first response was "hell no!". But maybe I'm a bit conservative? I just feel that as a woman and POC in our field (healthcare), she'll already have to work extra hard to be taken seriously.
Also, I'm much shorter and heavier than she is so she can't possibly borrow any of my pantsuits. Same applies to her other good friend in the lab. She moved recently to our area and spent some years in foster care, so she doesn't have family or people she could borrow from either.