Bahiyyih Khánum was born to Mírzá Husayn-’Alí, later known as Bahá’u’lláh, and Ásíyih Khánum, titled Navváb and the Most Exalted Leaf. Bahá’u’lláh and Navváb came from prominent families in the district of Núr in Mázandarán, Iran. Bahá’u’lláh’s father, Mírzá ‘Abbás-i-Núrí, entitled Mírzá Buzurg, was a celebrated calligrapher. Both he and Ásíyih Khánum’s father, Mírzá Ismá‘íl-i-Yálrúdí, held high-ranking positions in the government and were known as viziers. Almost nothing is known about Ásíyih Khánum’s mother.
Four sons of Bahá’u’lláh and Asiyih Khánum died in infancy and childhood. Two of them, Kázim and Mihdi, were probably dead before Bahiyyih Khánum was born. Of the other two, one lived to be several years old. His name was Alí-Muhammad. 'Abdu'l-Bahá speaks of him as a very clever, friendly and sociable child. The other, also named 'Alí-Muhammad, died in Baghdád in 1854. He was then about one year old. Bahiyyih Khánum’s surviving brothers were Mírzá ‘Abbás and Mírzá Mihdi. Mírzá ‘Abbás, later known as Abdu’l-Bahá, was about three years older than Bahiyyih Khánum; Mírzá Mihdi, entitled the Purest Branch, was about three years younger. He died at the age of 22 when he fell through an unguarded skylight in the roof of a section of the army barracks in ‘Akká, where Bahá’u’lláh and His family were imprisoned for two years.
- Baharieh Rouhani (‘Leaves of the Twin Divine Trees)