Dear Sarah,  

If you feel you are called, then tell God in prayer that you want to give yourself to him. Tell him you only want to love him above all things, and that your whole life is for him.  

Now, if your parents do not want you to go to the school in Rhode Island, there are a number of things you should do. The first is to understand that even though you want to go now, God wants you to wait, because at your age he wants you to obey your parents. Make sure that you use well whatever time you have to wait, be it months or years, to grow in your own love for Christ, and to do his work among your friends by being an apostle. 

The second thing to do is to persevere, and at the appropriate times speak to your parents about your desires. Perhaps they think it is only a childish idea you have and they don't want you to make a mistake; so show them by the life you live and by bringing the subject up now and again that it is more than that.  

The third thing is that maybe some of your friends may also have a calling, and maybe God wants to use you to help them discover it. You should form good friendships with them, and during your high school years watch out for each other. 

God bless.