My (24F) Aunt (55F) called me a gaslighter when I messaged my cousin (26M) saying that my grandfather was getting confused and that I thought the dementia might be hitting him harder than he lets on. To provide some needed context, I was organising to help my grandfather (83M) paint the inside of his home and had spoken to my cousin on the phone and said I'd be in my home town, would love for some help from him but that I'd mostly just like to catch up. It would be myself, my partner (28M) and my mum (52F) all lending a hand and hanging out. He agreed and we planned that we'd hang out and he'd lend a hand. A few days before the agreed date I messaged him to check we were still on but only got a vague half answer that he'd see how the weather was. Day we had planned to meet I messaged around 11am asking if he was coming to which he didn't reply until after 5pm that night. I messaged back saying I'd still like a hand if he was free the next day and let him know that it would be good for us to all be on the same page as my grandfather has been very confused with everything going on atm. (Other stressors and neighbour drama) I said that I thought he's playing it off but that the dementia is hitting him harder than he lets on and I was worried that when he comes over my grandfather will get him to do things that are wrong and it would be better for us to all be on the same page so my grandfather doesn't get confused. I don't get a reply from my cousin, but when my Mum called my aunt she abused my mother and said that I was a gaslighter, not a doctor and that I shouldn't be using the word dementia. That my grandfather only has "aging brain". (This is false btw, he does have classic symptoms of dementia, and while I know I'm not a doctor I understand enough to use the umbrella term "dementia" and not a specific diagnosis since he doesn't have one!) I apologised to my aunt in a message to be the bigger person but now I need to know.. AITAH?? All I was trying to do was help my grandfather, we drove 4hrs to help, my partner took an extra day off work to help and I am also currently going through cancer treatment but I was determined to help him. My cousin is not currently employed either. TIA Everyone.