According to Vishnupurana Ansh 1 Chapter 10, the wife of Atri, son of Brahma.

Antecedents: Vishnu – Brahma – Swayambhumanu – Devahuti – Anasuya.

Brahma’s son Swayambhumanu married Shatarupa and their children were Uttanapada, Priyavrata, Ahuti, Devahuti, and Prasuti. Devahuti was married to Brahma’s son Kardama. They had two daughters – Kala and Anasuya. According to Bhagavata Skanda 1 Chapter 4, Kala married Marichi and Anasuya married Vasishta.

Once, there was a drought for 10 years and the Ganga became dry. It was Anasuya who used her tapas energy to create food for the world and made the Ganga flow again. Once, for the devas, Anasuya extended a night into ten consecutive days. Rama, Lakshmana and Sita visited Atri’s ashram during their exile and met Anasuya there. Atri also told them about Anasuya’s tapas energy and their respect for her grew even more. Anasuya told Sita that the greatest tapas is serving one’s husband. She gifted Sita a necklace, other jewelry and a dress, and blessed that Sita would look her best when she wore these, according to Ramayana Ayodhyakanda Sargas 117, 118.

According to Vishnupurana Ansh 1 Chapter 10, Anasuya’s sons were Dattatreya, Durvasa and Chandra.  They were the incarnations of Vishnu, Shiva and Brahma respectively. (detailed under Atri)