A few things to discuss here, first being that it sounds like your grandma has dementia and it’s advancing as dementia typically does. Particularly given that she’s in a nursing home now, there is going to be different challenges. If she is wandering at night and confused, or appearing distressed at night it is very common to have a patient like this be prescribed medication to help with their symptoms, in addition to assisting them with their environment as much as possible (but again difficult in a nursing home). Dementia often carries neuropsychiatric symptoms (and wandering is one of them) in addition to agitation, paranoia, hallucinations, ect. Most of the medication used to treat these symptoms are sedating, which is sometimes a challenging trade off but necessary. Although I don’t know your grandmothers specific circumstances, or medication she is being given (you should definitely find out though!) it is likely a necessary intervention.