Track suit trousers don't have to be shiny ones with go-faster stripes and/or garish branding. Plain cotton or polycotton ones can look smart with a sweatshirt, and if the sweatshirt has a school badge on the chest the whole ensemble can look perfectly ok for learning in. I've remembered that my children wore a white polo short under the sweatshirt, so if the weather was warm they could take the sweatshirt off. Again, that looked smart and was practical. Mine were very young, but I can't see why older pupils wouldn't look fine in them too. Trousers come in all shapes and cuts, and not all suit all girls. Teenagers in particular vary hugely in size and shape, and a 'school' pair is by no means going to be suitable for all. When mine were at middle school they allowed trousers for girls, but they had to be bought from the school, and my daughter looked awful in them and they were uncomfortable. Boys, OTOH could wear any black trousers. Apparently this was to stop girls wearing hipsters that might show off their figures too much ๐. I complained, but got nowhere with it.