you have a 18 year old daughter that is expected to be a built-in babysitter and watch a younger sibling even though she already has plans
a older child or grandparent that is expected to babysit often
"you have a 18 year old daughter that is expected to be a built-in babysitter and watch a younger sibling even though she already has plans" What is the definition of "built-in babysitter"?