Sri Sarada Devi

Short biography
Millions of people call Sarada Devi (22 Dec. 1853—20 July 1920) Holy Mother. She was an unlettered mystic, but she advocated education for girls. Swami Nikhilananda, one of her disciples, describes her as the symbol of spiritual aspiration of women everywhere and portrays her thus: 
“When Holy Mother came to Dakshineswar at the age of sixteen, Sri Ramakrishna asked her whether she had come to pull him down to a worldly life. Without hesitation she said, ‘No, I am here to help you in the spiritual path you have chosen to undertake.’ From then on, Holy Mother lived with Sri Ramakrishna as his spiritual companion, devoted wife, disciple, and always the nun. … She never missed communion with God, whom she described as lying in the palm of her hand, though she was engaged day and night in various activities.”
“Holy Mother was an unusual awakener of souls. With her disciples she served as teacher, dissolving their doubts, as mother, who through love and compassion won their hearts, and as the Divinity, who assured them of liberation. Herself nearly illiterate, through simple words she taught them the most profound truths. Her affectionate maternal love tamed their rebellious spirits; but her great power lay in her solicitude for all. Often she said, ‘I am the Mother, who will look after them if not I?’ She encouraged them when they were depressed because of slow spiritual progress, and she took upon herself their sins and iniquities, suffering on that account.”
….. (Unlike Ramakrishna), “Holy Mother lived as a simple householder, surrounded by quarrelsome and greedy relatives. As a teacher, she taught,  the realization of God alone is real, and everything else, impermanent.”
“In case they had any problem which seemed to be insoluble, the disciples of Ramakrishna in charge of the Order after his name, used to take her guidance. The revolutionaries of Bengal …. used to question her about her intuition regarding the prospect of British rulers’ leaving India. She told them that it was not possible for them to oust their rulers and that their days would come when Europeans would quarrel among themselves.” 
Shri Sarada Devi

Sri Sarada Devi
Sarada Devi and Sister Nivedita

Some teachings of Sri Sarada Devi
“If you want peace, my child, see nobody’s faults. See your own faults. Learn to make the world your own. No one is a stranger, my child. The world is yours.””One suffers as a result of one’s own actions. So, instead of blaming others for such sufferings, one should pray to the Lord and depending entirely on His grace, try to bear them patiently and with forbearance under all circumstances.””You see, my son, it is a fact that you will face dangers. Difficulties always come, but they do not last forever. You will see that they pass away like water under a bridge.””Pray to God with tears in your eyes whenever you want illumination or find yourself faced with any doubt or difficulty. The Lord will remove all your impurities, assuage your mental anguish and give you enlightenment.””Always do your duty to others, but love you must give to God alone. Worldly love always brings in its wake untold misery.”On Love and Compassion: “Let me tell you how to love all equally. Do not demand anything of those you love. If you make demands, some will give you more and some less. In that case, you will love more those who give you more and less those who give you less. Thus your love will not be the same for all. You will not be able to love all impartially.””Whenever you go from one place to another, observe the things around you, and also keep yourself well informed about what happens in the place you live. But keep your lips shut.”On the necessity of work: “It is essential that one should work. It is through work alone that one may break asunder the bonds of Karma; only then is one free of desires. One shouldn’t be without work even for a single moment.”

Books/References on Sri Sarada DeviHoly Mother: Sri Saradadevi – By Swami Gambhirananda – Chennai Math | Advaita AshramaThe Gospel of the Holy Mother – OnlineSri Sarada Devi, The Holy Mother – By Swami Tapasyananda – Chennai Math | OnlineTeachings of the Holy Mother – OnlineHoly Mother – By Swami Nikhilananda – Chennai Math