Hi forgottenmyname, well there is no answers to this solution only responsibilities to whom that are prepare to succumb. Cuba is quite a close community and strong family ties, so it just goes to show you that dementia still to the majority is something totally confusing and difficult to accept.
Hopefully the Internet might educate the majority in the world who are caring and prepare to sacrifice some time on the net to educate themselves about this problem that eventually may happen to all of us, but you know what people are like they always think it will never happen to them, but I'm sure it is going to be an extremely slow process.
As for your auntie, you have to remember she is the only one who have stepped forward and prepared to lend some help that is what matters, it is no use trying to judge her ability to comprehend this situation the only thing that matters who stepped forward to help, any help is better than no help.
But if you are determined to do more for your mum you can try to gather information over here on the possibilities of bringing her over on compassionate grounds. But I'm sure you are going to have to succumb to some difficulties, as the society will see it that it would be additional stress on the existing system over here.
Sadly our society are not prepared to accept or interact with people who have dementia, I was also an antique collector and dealer previously you could always see us on cash in the attic, but the dealers at the auction house I used to visit, don't seem to be able to accept people with dementia amongst them, I was told by a prominent dealer in one of my favourite auction house that he did not understand why I brought my wife there, so I had to stop going because it's clear that she was posing a problem to them. Well she was all so posing a huge problem to me, but I was prepared to succumb to all the difficulties that occurred believe me there is a huge amount to deal with, but after all she is my wife that I promise to take care of till death do us part.