Thank you for your message, I will do my best to help.
As this matter involves a person that is deemed to lack capacity, any action taken will have to go through the Court of Protection first in line with the Mental Capacity Act as oppose to the Human Rights Act. You will not be able to litigate/claim on behalf of your sister in any other Court relying on the Human Rights Act until you receive permission from the Court of Protection.
The Court of Protection will consider an application to move your sister to suitable accommodation that meet her needs but you will have to provide strong supporting evidence and it has to be financially viable. If your sister is entitled to Local Authority (LA) funding, you will need to speak to the LA of your choice and obtain an offer in principle with details of the home and enclose that with your application to the Court.
The Court of Protection will make their decision based on the information you provide them.
Please see link below to the official government website to start your application to the Court of Protection:
I hope that helps.
Best of luck,
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