Total bias but I have made my kids dress up more than usual. Both chafed and later agreed. When I see a kid with leggings or jeans, my first reaction is that the kid isn’t that interested. For those who haven’t been to an interview, most parents are in suit jackets ( women too) or professional dress ( not really business casual). Kids are often dressed up quite a bit ( Boys in suits and ties and girls in dresses or nice slacks). Make sure you wear comfortable shoes.