A few months after her arrival to Beirut, American Protestant missionary Catherine DeForest wrote a note to her brother-in-law, a merchant in New York, requesting that various items be sent to her from the United States. This included “Two Muslin dresses for Khozma [Witwat] and Lulu [Shibly] to be alike.” Although only an addendum to a longer letter, this note, requesting American-made dresses for the two “adopted” girls living in Catherine’s home, illuminates the forging of a complex transnational family network that linked Catherine, her husband Henry, their families in the United States, with her new “missionary family” on the field, the young girls who resided in the DeForest household, and the students of the DeForest Female Seminary in Beirut during the mid-19th century. Drawing upon research of personal correspondences, Mission Church records, and the Sijil of the Syrian Protestant Church, my paper investigates the complexities over what defined a transnational family residing in Ottoman Beirut during the mid-19th century, the relationship between members and their varying embodiments of power, and different perceptions of this family by its members and of their position within it. It will focus specially on the experiences of three children in the family: Charles Smith, the child of another missionary couple who was placed in the care of the DeForests after the death of his mother, and Kozma Witwat and Lulu Shibly, two Syrian children who were “adopted” by Catherine and Henry and lived in the family during the DeForests residency in Ottoman Syria. In addition to highlighting the central, but often overlooked role of extended family relations in missionary encounters, this study will explore the complexities of developing and defining families, as social and legal relationships, within a new religious community in the Ottoman Empire, the Protestant community, that was only legally recognized as an independent millet in 1850. Exploring the transnational DeForest Family thus offers a unique insight into family life during a dynamic period of encounter and social transformation in the Ottoman Empire of the mid-19th century, as experienced by American and Syrian members of this hybrid family, and during a period when the state had minimal role in defining and regulating families amongst Christian communities during the era of legal transformation of the Tanzimat.