This paper aims to extend research on the association between mother-child contact and adult children's psychological well-being in later-life families by differentiating between in-person, virtual, and written digital contact, examining the moderating role of children's gender, and exploring the processes that underlie these associations. Mixed-methods data were collected from 250 adult children nested within 131 families as part of the third wave of the Within-Family Differences Study. On average, adult children were 59 and mothers were 88 years of age. Multilevel analyses revealed that interacting with mothers through written digital media was associated with higher depressive symptoms among adult children, whereas mother-child in-person and virtual digital contact was not associated with children's depressive symptoms. When stratifying the sample by children's gender, we found that mother-child written digital contact was associated with higher depressive symptoms among daughters, but not sons. Qualitative analyses suggested that adult daughters' psychological well-being was negatively associated with written digital contact with their mothers because this medium of interaction typically fell short of daughters' expectations for emotionally enriching exchanges. This study revealed differences in how virtual and written digital contact are associated with psychological well-being among adult daughters, but not sons, suggesting that it is important to consider type of contact, gender of interactants, and content of exchanges when studying the associations between digital communication and relational and psychological well-being and designing intervention programs and digital communication technologies.