If they are close together the cord is loose, but whenever the mother and child are separated, either physically or emotionally, it stretches tight and pulls on the mother's heart. Things like the mother returning to work and leaving her baby in child care, the child's first day of school, or when he or she goes to visit a relative or to summer camp without the mother, pull the cord tight. And if the child is hurt, sick, or in trouble it pulls tighter still.
When the baby becomes a teenager he or she might try to reject the tie to the mother's heart, but that only pulls the cord tight since it can't be cut.
When the child becomes an adult and moves out into the world away from the mother the cord continues to stretch between them, although it has become longer. As long as the grown child stays in frequent contact and on good terms with the mother, it can be relaxed, but if there is conflict between generations or the child and parent don't stay in touch, the cord again tightens and pulls on the mother's heart.
Eventually when the mother becomes old the child might become the caregiver and when she dies it's the child's heart that feels the painful pull.
But the cord connecting the hearts of a mother and child cannot be cut.
The name of the cord is Love.