Untitled - The lesson being taught to this young lady is not that 'some rules are stupid and should be broken...'
It's 'pick your battles, and work out when you can win - or not ...'
And thus is a battle she will lose all day every day.
Uniform is designed to ensure that no-one can disrupt by being a one-peron ego-fest, but most importantly, the disadvantaged pupils are nor identified by their parents' financial inability to keep up with trends in clothing, hairstyles, and so on.
You may see school uniform as a 'stupid rule', but many pupils give silent thanks for it, when they can fit in, and not be ostracised for not being expensively dressed.