I would be willing if it only involved her fixed income. But we recently sold her house and she now has a large sum of money in her account. If we manage it carefully she can live comfortably for several years. If not, she will not be able to afford where she lives now and anything else will be a major step down.
Her years of depression/anxiety have made her dependent on several drugs - Klonopin and marijuana specifically. She is not allowed to smoke where she lives now so I suspect she’s having withdrawals and wants to move somewhere she’s free to smoke. However, although the pot helps her mood wise, it also makes her unsteady on her feet. She’s suffered several falls - broken back twice, broken foot, bruising literally from head to toe. She is now in a very safe, upscale senior living center. And she’s turned on me accusing me of keeping her in the dark about her finances. What do I do? Turn it all over and walk away?
Meanwhile, try to set her up for success by putting as much on autopay and direct deposit as possible.
She might be a good candidate for a single premium immediate annuity for a fixed period that will direct deposit into her account just in time to pay her rent. (NOT a variable or "investment" annuity.)
We went through all types of hand-stands and enabling to get my in-laws to stop spending, see the light, stay on budget, just get a part-time job, blah blah blah. We found the print-out of the budget plan ripped up in their trash shortly after that meeting. For some people it is not a matter of reason or logic. I agree your sister may be behaving like an addict. In which case you definitely shouldn't enable her. You can't have her recovery for her. Whatever is going on inside her, she needs to want to improve her situation more than you want it for her. I wish you clear boundaries, much wisdom and peace in your heart.
So it is in the end simple. If she is of sound mind the choices are hers. If compromise as I suggested does not work, and she wants control, then explain to her that you will walk away if she ruins her financial situation, and that you will never discuss it again, and when she is thrown into the worst facility that exists you will not mourn the fact, that you will visit, but you will realize she made her bed, and it is hers.