She was the daughter of a good and wealthy merchant of Ujjení. Having come of age, she was given in marriage to the son of a merchant in Sáketa.
For one month she lived with him as a devoted wife; then because of her past kamma, her husband became estranged from her, and turned her out of the house. She was married again with the same result, and a third time to a friar. Isidásí's father persuaded him to give up the pilgrim's life; he dwelt with his wife only for a fortnight and refused to stay with her any more. Isidásí then met the therí Jinadattá, whom she entertained to a meal at her house. Under Jinadattá, Isidásí joined the Order and became an arahant.
The Therígáthá (vv.400-47), which contains forty-seven verses ascribed to her, describes not only her present life, but also her past lives. She had been a worker in gold in Erakaccha and had committed adultery in that life. As a result she was born in hell for a long time, and, in subsequent births became an ape, a goat, an ox, a hermaphrodite slave and a carter's daughter. In this last birth she was sold to a merchant in payment of her father's debts. When she was sixteen, the merchant's son, Giridása, fell in love with her and married her. He had already one wife, and the new one caused dissension between her and her husband. Therefore it was that in this life she was hated by her husbands. This account of her sojourn in samsára was related by Isidásí in response to a request by one of her fellow-nuns, Bodhí (ThigA.260ff).
Mrs. Rhys Davids thinks (Sisters, Introd. pp.xxii f) that Isidásí's verses in the Therígáthá suggest late literary craft and bear the impress of late literary creation. The scene is Pátaliputta, and not any of the usual towns mentioned in the Canon, and the name of Isidásí's sponsor – Jindattá - is, she says, significant. Perhaps there are traces here of Jainistic influence.
In the Dípavamsa (xviii.9) Isidásí (Isidásiká) is mentioned in a list of eminent therís who were leaders of the Order of bhikkhunis.