There's like people who do baby-sitting, that is look after infants and toddlers for the parents. What do we call people who do this for the elderly? For example, my friend hires a "elder-sitter" for her mother. It's not a professional, just someone who knows how to care for the elderly.
Is there a name for this person?
Caregiver is the professional term. I'm not certain if there is a less formal word.
caregiver |ˈkɛrˈgɪvər| noun a family member or paid helper who regularly looks after a child or a sick, elderly, or disabled person.
It can carry a slightly negative/mocking connotation, but the closest term I've heard to what you're asking for is granny-sitter.
(Others have given the more formal/polite terms such as carer/caregiver, though these might be taken to imply either a professional role, or a permanent duty due to family ties.)
