Most of Qurrat al-'Ayn's considerable output of apologetic writing has been destroyed or lost.

Unfortunately, there is good reason to believe that most of Qurrat al-'Ayn's considerable output of apologetic writing has been destroyed or lost. Something of the extent of this output is indicated by Muḥammad Muṣṭafá al-Baghdádí. He says that, when she was in Kirmánsháh in 1263/1847, letters would arrive for her every day from ulama and other enquirers. She would write rapid replies to all of these. The anonymous Azalí history, Qurrat al-'Ayn: bi-yád-i Şadumín sál-i shahádat, states that, while under house arrest in Tehran, 'Izziyya Khánum, Şubḥ-i Azal's eldest sister, would send her younger sister Fátima to visit her, Fátima then being eight or nine years old. The little girl would bring letters for Qurrat al-'Ayn concealed in her pocket and would take replies away in the same manner. Many prayers, poems, homilies, and other pieces reached the Bábís in this way, and many of the originals are still extant. These copies may be in the possession of 'Izziyya Khánum's family, but it is possible that some are in Bahá'í hands as well.

(The sources for early Bábí doctrine and history A survey by Denis MacEoin)

https://bahai-library.com/pdf/m/maceoin_sources_babi_history_proofed.pdf