Aren't families wonderful!
No, the one sibling has no right to do what he has done. But there will be some reason put forward as to why he did it. It will all get very tit for tat if someone else puts a new lock on, unless they all agreed to something.
Technically, that life interest endures until the person dies. Someone who is Compos Mentis would waive their life interest . The person could be made a Ward of Court and orders sought if necessary.
When she dies, the Death Certificate is all that will be required.
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