Abstract Drawing on an ethnographic study on different groups of left-behind women (mothers, aunts, and grandmothers) in Fuqing, a major transnational migrant-labor-sending area in China, this article examines how they collaborate with their overseas family members in childrearing through digital media use. Applying the “im/mobilities” framework, this study explains how different left-behind caregivers use mediated communication as communicative mobilities to negotiate family roles and relationships in situated transnational power geometry. Despite the common structural constraints (rural patriarchy and inadequate social resources), left-behind women’s socio-structural immobilities vary depending on their specific relationship with migrants (conjugal, kinship, and intergenerational dynamics), which embodies the asymmetrical nature of transnationalism. The findings highlight the dynamic negotiation between left-behind caregivers’ communicative mobilities and their contextualized socio-structural immobilities, which leads to diverse forms of agency and disempowerment. This article shows that communicative mobility is not only manifested as media use but also embodied as media (non)use. Lay Summary Transnational labor migration has allowed people in poor areas to improve their financial well-being, but has also caused separations among many families. Thanks to the prevalence of various digital media (e.g., instant messaging, webcam and voice calls, and social media platforms, etc.), fragmented family members are able to maintain and manage different family relationships despite geographic constraints. This study draws on three groups of female caregivers (mothers, aunts, and grandmothers) in Fuqing, a major transnational migrant-labor-sending area in China. I am particularly interested in how these left-behind women collaborate with migrant parents to fulfil their duties of raising left-behind children through digital media. The findings suggest that left-behind women’s life experiences are not only related to gender norms and inadequate social resources (e.g., a lack of job opportunities and robust social welfare system) in rural China, but also pertinent to their specific relationship with migrants (e.g., conjugal, kinship, and intergenerational dynamics). While female caregivers’ different situations influence their media practices during childrearing collaboration with migrant parents, such media engagement also contributes to the shaping of their transnational family relationships.