How do I politely remind my aunt what dementia is.

My mom has early onset dementia. She's still in the relatively early stages, but I have to take care of her. My aunt asked me to tell my mom not to call after 3pm (we are West Coast, they are East Coast). There is literally no way my mom will ever remember this. I could post it on the fucking walls and she'd never notice the massive poster. My aunt is fucking delusional. I want to say "Are you a fucking moron and do you know what dementia is?"

How do I say that much more politely.