Welcome to this page.
I personally think that you should tell! Whatever happens is for the best, don't worry if she doesn't like you back, there's a chance that she does, and this chance could be very important. I remember I liked someone in primary school too, I was keeping it a secret for ages and ages, I had sent them lots of notes saying that and in the end they knew. They didn't like me back but I took the risk and nothing bad has happened! We are still great friends!
Thanks for choosing MARRs and