Assalamu alaikum. I got a reply to my question with a request to give further information.
My grandma has been diagnosed with dementia via doctors. She remembers a few things from the past not all. However she doesn’t remember or recall recent events. She gets confused with the days and months also. She needs reminding to take medication, what days to go for a bath, who certain people are etc.
Also by rent money I should have clarified. My grandparents house is in a line of businesses so the front of the house is a shop and is currently on rent. So by rent, I meant the rent that accumulates through the shop that is on rent. After my grandfather passed away he stipulated in his will that everything went to my grandmother.
Also from your answer I get the impression that permission from my grandma needs to be sought before spending on her behalf, does this apply to everything such as charity ventures, giving gifts to family etc? Can I not donate in charity or give gifts on her behalf with her money?
Also a last note, if it makes any difference, I do have a power of attorney in my name to act on behalf of my grandmother legally.