I have been caring for her since 2015, is in a nursing home where I visit often and care for her. Her brother wants to take her to Puerto Rico where things are not good. She can't walk or stand. Can he take her there and take over because she is 72 years only. He has never cared for her and does not even call her or look out for her.
You raise a good point, that PR is still trying to recover after being devastated by a hurricane. Services still aren't even operating in some areas. It's not an ideal place for someone who needs care.
Does he even have the financial resources to move and care for her out of his own funds?
Her brother has no standing to change where she lives or how it is paid for.
Is he in PR now? I'd make sure the nursing home staff knows not to allow your girlfriend leave the premises with anyone without your permission.