quality - an essential and distinguishing attribute of something or someone; "the quality of mercy is not strained"--Shakespeare

maternal quality, maternalism, motherliness, maternity - the quality of having or showing the tenderness and warmth and affection of or befitting a mother; "the girl's motherliness made her invaluable in caring for the children"

fatherliness, paternal quality - the benignity and protectiveness of or befitting a father; "the gentleness and fatherliness of the strange old man eased her fears"