Companion Care Needed For My Mother In Palo Alto

I'm looking for companion care for my mother in her 80s with early Alzheimer Dementia. She is highly functional, cooks for her self, dresses self, takes care of personal hygiene. She has left the apartment late at night a few months ago. Duties include providing companionship and preventing leaving the apartment at night. Preferences for a caregiver who is a non-smoker.