If you get engaged during high school then depending on your school you may get kicked out. I know that that’s the case in my school. You’ll then have to get a GED if you ever want to get a degree or a decent job. And even that isn’t always considered as good as a diploma.
Either way, if the question is really “should she rush in order to be the first one” then absolutely not. If you’re getting married just for the sake of being first then you need a big reevaluation of priorities. If that’s just incidental and not the reason behind it then there is no way to say anything without knowing you personally. I don’t want to make generalizations. What I said here is based solely on the tone from your posts.
Good luck with whatever happens!
Oh and I just realized that you’re not talking about yourself. In that case, please change the word “you” to the word “one”. 🙂