Oh dear Candy. Parents here did that, followed me whenever I moved. Can you stand firm and tell her you cannot help her in the way she might need if she moves there? What does sister say? I also agree with Sept. If you can tell her you're moving, maybe she won't come. Perhaps you can tell her that you are considering moving to where your sister is so the best place for her to go is up where sister is.

Keep breathing. It's not a done deal yet. And you are renting so you're not tied to that area. Let us know what happens.