Human blood relative.
Cat.
It's easy to understand why posters believe that the wishes of the elderly human relative in need should take second place.
I don't know if you've read the history on this, but we did not put my cat before my aunt. My aunt was diagnosed with moderate dementia, and she was difficult about many more issues than just the cat. Our concern regarding the cat was that she was going to poison it because she was getting more irrational. She is living in a beautiful (and expensive) one-bedroom apartment in a senior assisted living resort with 24-hour care, and she is very happy, unlike when she was living in her neglected house. I see her several times a week and attend to all of her affairs, personal and medical. She is doing better with all of the peer interaction, too.
So please refrain from judgment until you know the whole story.