Grandma needs meds. Seroquel is used a lot in dementia, same with melatonin.

She is “show timing” for relatives and “sundowning” with you. “Confabulation” aka telling stories is an unfortunate symptom of dementia, too. Alongside paranoia. Your relatives ought to know better if they work in healthcare

She doesn’t hate any of you…you’re just the ones there and so you’re the ones she’s going to suspect of doing XYZ.

She’s not doing it on purpose, her reality is distorted and she genuinely believes she’s in danger. She is likely in anxiety overdrive 24/7 trying to keep even the most basic things straight (do I live here?) and she likely needs some daily meds to help give her peace of mind.

Does she see a neurologist who can work with your family to help tone down some of these symptoms?