Your mother met the Hashira when they were young, she was practically a comfort zone to all of them, and you happens to look just like her. When the Hashira first met you they thought you some reincarnation of her but you were her child, sometimes you were called by her name by accident or they talked with you, saying you look exactly like her, you how ever never liked being called your mother. You were sitting alone at your Estate, thinking it was time to talk them to not call you it anymore.