Any rose experts here? I'd like help/advice if you're willing... [View all]

I have a rose tree (Chicago Peace, if that matters) of great sentimental value to me.

It was planted May, 2010.

This morning, seemingly overnight, a new little tree has emerged right next to it.
Very close, but not attached, at least above ground.

I'll admit I'm a complete dunce, and it's a wonder this thing has survived my brown thumb these four years.

How has this happened? Is it growing out of the larger one underneath the soil?

Is there a way of detaching it and replanting it somewhere else?
I don't want to kill it if I don't have to, as I said, it has great meaning to me and killing any part of it would make me sad.
However, I don't want to risk the health of the larger tree.

I'd love to be able to grow a second one, if possible. Or, can I leave it as is, safely?

Any advice greatly appreciated as I am a

Thanks!