I'm thinking of joining a demonstration exclusive to the women of my school
Why are you going the women's demonstration?
Because it's our time to make a change for the better.
It is okay to join  protest on what you believe. As long as it is peaceful and you are going to heard on what you stand for.
The protest should be inclusive of all people. If it was an exclusive protest, no one would join.
I tend to agree with you, they should allow anymore to protest women's rights.