You need to sit down with her and tell her what you’ve observed.  Then tell her you’re concerned and see if you can figure out what she’s feeling and why.  Perhaps she’s actually gotten depressed in her new environment.  With my Mom. we found out she had developed cancer and was in pain all the time.    With your Mom, maybe she’s gotten lonely and needs you to visit with her more often.If she seems depressed, perhaps your Mom would be willing to see a social worker, psychotherapist or a doctor who could prescribe her appropriate medication. Tell her you love her but you need her to help you and herself by keeping as cheerful and grateful as she can be.     If she is just being “difficult,” maybe a POP coach could help you and her.