How about inventing ‘skorts’ - half skirt and half shorts?
Not sure what exactly it would look like, but the teachers would not be able to ban you.
It could become fashion sensation!
They have been making those for women for many years already.
Culottes
Nothing new about skorts. My wife has worn them for years.
Don’t think they ever became a sensation though.
Those already exist. Common cheerleader and tennis player garment.
Just get a plaid skirt and wear as a kilt—or a real kilt (or a green Irish Kilt) Say its your heritage to honor your people.