According to the Commentary (AA.ii.596), she was the daughter of Bimbisara. The king gave her five hundred chariots for the use of herself and her companions. Cundi’s brother was Cunda as mentioned in the family chart of Bimbisara.
She visited the Buddha at the Kalandakanivāpa in Veluvana where Buddha preached her the Cundī Sutta (A.iii.35f). Cundi visits the Buddha and tells him that, according to her brother, Cunda, those who take refuge in the Buddha, the Dhamma and the Order and refrain from the charm of life, theft, lusts, lying and liquor, will be born in a happy condition after death. She wished to know more of this doctrine. The Buddha explains to her that the Tathagata is the best of beings, the Doctrine which leads to Nibbāna is the best of teachings, the Tathāgata's Order is the best field of merit, and of virtues, those beloved by Ariyans are the best. Her name occurs in a list of eminent upāsikās. A.iv.347.