How to reach a specific person?

I am new to this website. I registered. I found a person that graduated from the school I am interested in. However, I had to send her a "friend request" and this did not allow me to type anything in to let her know why I wanted to be her friend! She could easily reject since she doesn't know me. Is it possible to email someone? I think I tried that and it said I have to have 15 posts before I could do that?!?!?!?! I really want to reach this person and ask them about their experience at that school. Can anyone help? Thanks!