My dearest little sister,

It's exciting and scary to watch you fall in love with someone.  You and I both know that it's not a petty crush either, and we both know that we don't really know what it is, for neither you nor him.  There's a lot I wish I had the words to say, but for things like this, there just isn't.

I hope you always come to me and talk like we do now. I've grown to value our friendship so incredibly much, and I can honestly say that you're not only my sister but my closest friend.  We've been through hell and back, we both know that, and we both know it's not going to be easy these next few weeks.  But we'll keep fighting, and we'll only grow stronger because of it.

I suppose the reason this is so odd to me isn't the fact that you're in love with him, but that it makes me older to see it.  I look at you and I know what those little touches do to your heart, and the way his smile makes your breath stop in your throat.  I watch you with happiness, and a little sadness, knowing that he, too, will leave on a mission and you will go through what I am.  It's not something I would wish on anyone, but I know you're strong enough to make it through; we both are.  It'll be rough, just as I know you understand, but I hope you know I'm always here for you, even if it's two in the morning and you're still up crying because the world is simply too vast.  Remember that I've been there, and remember that I am still there sometimes.  Maybe I can offer you the comfort I've come to know, and the understanding of what love can really do.  I hope you don't give up on him, either, like everyone is telling you to do, because I know that look, and I know that it's not something that will go away easily, if ever.  Don't listen to them; even if they're right, take what makes you happy and run with it, because it's no use dwelling on the negative outcomes of what-if.

Dearest little sister, I love you and care for you and hope the best for you.  We're both long old enough to make our own decisions and understand the complexities of our hearts, but know that I will always do what I can to help you.  Unlike so many people in the world, we've found what it truly means to be sisters, and I cherish that more than you know.

Take care sis.  I love you much.