Does this seem like dementia?

My grandmother who is 90 now was diagnosed with Covid during the Omicron wave in Jan 2022. She was asymptomatic. But after testing negative, she started developing some symptoms like irregular bowel syndrome. She would complain of diarrhoea one day and the next day complain of constipation. She started eating less and less everyday. Now she is having trouble swallowing food and even medicines. A caregiver who used to take care of her before had come in the other day and grandma got scared of her. She was saying things like she is afraid the caregiver could be possessed of evil spirit who has come to give her illness. That was concerning for us but that was just one instance. She is finding any smell in regular food too strong, too sweet, too salty, too spicy for her tongue. Recently she complains of hands and body shaking but nothing is visible to our eyes. And also complains of throat issues when in air-conditioned room. Are these signs of dementia? Thats what our doctor is going for!