Daughter from California syndrome (first documented in 1991)is a mental disease wherein a person feels guilty from being absent from the life and care of an elderly patient and thus try to reassert their role as an involved caregiver where they come off as  angry, articulate and informed.
The phrase was first documented by David Molloy and other gerontologists in a 1991 case report published in the Journal of the American Geriatrics Society, titled "Decision Making in the Incompetent Elderly: 'The Daughter from California Syndrome'". They may feel guilty about having been absent, and may therefore feel motivated to reassert their role as an involved caregiver. "Daughter from California" syndrome is a phrase used in the medical profession to describe a situation in which a long-lost relative arrives at the hospital at which a dying elderly relative is being treated, and insists that the medical team pursue aggressive measures to prolong the patient's life, or otherwise challenges the care the patient is being given. The "daughter from California" is often described as angry, articulate and informed. 
