Purpose: The life course perspective suggests that serious physical or mental health conditions that limit the daily activities of any one family member are likely to be consequential for other family members as well. In this article, we explored whether adult children’s serious health conditions affected the flow of expressive and instrumental support between mothers and both the offspring with health conditions and other offspring in the family. Design and Methods: We used data collected from 369 older mothers (M = 78 years) regarding 1,338 of their adult children (M = 49 years), as part of the Within-Family Differences Study-II. Results: Adult children with serious health conditions were more likely than their siblings to be given support by their mothers. The presence of adult children with health issues did not reduce mothers’ provision of expressive or instrumental support to their children without health conditions. However, in families in which a higher proportion of children had serious health conditions, mothers received expressive support from a greater proportion of their healthy adult children than in families with a smaller proportion of adult children with health conditions. Implications: These findings contribute to a growing body of research demonstrating the ways in which conditions in adult children’s lives affect their mothers.