You say that will not work for you and your life. If things should change, you'll let her know.

She will complain, guilt, cry, and probably try and manipulate you.

You point out her behavior and you say that you are incapable of dealing with that type of behavior. I would also research assisted living facilities near her friends and current life.

You can start out kind and nice, the truth is that you may need to get ridiculously blunt in order to drive the point home.

There are some parents who get it and some who don't.

My narcissistic abusive entitled mother made a similar declaration. I told her clearly that would NEVER happen.

She tried everything to get me to commit. I told her that she lived her life on her terms --- she doesn't have the right to make decisions for my life. I explained that we would look into whatever nursing home she could afford if she decided she couldn't live on her own.

Be clear, have a plan, don't allow yourself to be manipulated.