I care for my mother-in-law who suffers from Dementia. Her behavior is very very aggressive. How do I handle her behavior?

She is very attached to her personal belongings and doesn't let anyone keep them organized for you. She forgets and constantly accuses everyone around her of stealing her stuff. It has become very difficult to be around her. All she likes to talk about is her finances and her favorite activity is to keep switching spots of her valuables and then accuse others of taking them. She cries like children. She often wakes others up at odd hours and want them to look for her stuff. She is very attached to my toddler and wants him around at all times and expects him to talk to her as an adult would. If he doesn't she complains to my husband that I tell my child to stay away from grandmother. It is both physically and mentally challenging and exhausting to care for these patients. How should I go about taking it easy?