grandmothers
Grandmothers are women who are mothers or grandmothers to someone else's children. They are usually very close to their grandchildren, and they often take care of them when their parents are away or busy.
My grandmother is a great grandmother, which means she is a grandmother but her grandchildren are not her own.
My grandmother is my mother's mother, which means she is my grandmother's mother but her grandchildren are not her own.