I'm going to tell my sister not to move back to ca
Have you talked with her about this before?
I used to tell her that, but she just complains me about her need for a change of environment.
If that is what she really wants to do, you should try to support her. I know that you will miss her, but she should live where she will be happiest.
I know, I just want her to come home, but we will always love her.
I'm glad to hear that you are ready to accept your sister's wishes, even though you will miss her so deeply.   Just remember that she is happy where she is, and that she will always love all of you in return.