A. The religious orders of Roman Catholic sisters, or nuns, have kept very good records of their members. Often, this information will include the birth place of the nun and her parents’ names. Sometimes even the parents’ birth places are given! In order to find records for your great-great aunts, you need to first find out what religious order they belonged to. If you can find an obituary for one of them, it should state this information. You can also tell by the initials after their names, such as with “Sister Mary Joseph, OCD.” Religious sisters usually took on new religious names when they joined the order. The initials at the end of the name refer to their particular order or “congregation” (in this case, OCD stands for the Discalced Carmelite Nuns).
Once you have the religious order identified, then you can look up their national or provincial motherhouse/headquarters address in a modern edition of The Official Catholic Directory (P.J. Kenedy & Sons, available in libraries), which is published annually. This directory also gives the abbreviations corresponding to each religious order. Usually each order (or province of that order, if it has a large membership) has an archivist who will assist with enquiries like yours.
By the way, the same excellent biographical information can generally be found for Roman Catholic priests and religious brothers, in the archives of their religious orders, dioceses and seminaries. So in your research, don’t ignore your ancestors’ sisters and brothers who went into religious life. Their records may hold the key to important facts about your family, such as their place of origin abroad.