Popularly known as Mai Fatto, was the wife of Baba Ala Singh, founder of the Patiala family. She was the eldest daughter of Chaudhari Khana, a zamindar of Kaleke, in present-day Sangrur district of the Punjab. It is said that at her birth her parents, disappointed at having a female child, put her in an earthen vessel and buried her alive.

A holy man, Dyal Das, in the line of Bhai Bhagatu, happening to pass along and, seeing the mother in tears, enquired the cause of her grief. On Dyal Das's advice, the child was dug out from underneath the earth unhurt. As she grew up, she came to be known by the, name of Fatto. She was married to Ala Singh in 1707 and bore him three sons, Sardul Singh, Bhumia Singh and Lal Singh, all of whom died in the lifetime of their father, and a daughter, Pardhan Kaur.

Fateh Kaur was a devoted housewife. She helped her husband in matters of state as well. It was she who at the time of plunder of Barnala took the initiative and appointed a deputation to negotiate peace with Ahmad Shah Durrani who was on his way to Kabul after the battle of Panipat (1761). She was able to secure peace on payment of a tribute.

It was also owing to her influence that Baba Ala Singh had the support of the descendants of Bhai Bhagatu, one of the most revered Sikh families of the Sutlej territory. Bhai Gurbakhsh Singh of this family, who founded the state of Kaithal, helped Baba Ald Singh in his conquest of a large number of territories, including Budhladha and Tohana.

Fateh Kaur lovingly served the Dal Khalsa and kept an open Guru ka Langar for them. After the death of Baba Ala Singh, Fateh Kaur installed her grandson, Amar Singh, on the throne of Patiala. Himmat Singh, half-brother of Amar Singh, raised a revolt against him, but Fateh Kaur intervened and brought about a compromise between the two.

Fateh Kaur, who is counted among the builders of Patiala state, died in 1773 at Patiala and was cremated near Baba Ala Singh's samadh, in the area known as Shahi Samadhan, the royal cemetery.