if she gets more odd behaviors after 3 in the afternoon that is called sundown syndrome. lots of people with dementia get "worse" as the day goes on. You must get away even for just an hour or two, it might be best for her if you do this in the mornings. feel free to PM me, if I can help I will,maybe not in person at least give advice. some nursing homes offer daycare in these situations that may be an option for you.