Objectives: Nearly 80% of children within the U.S. live with a sibling, and siblings exert a unique and typically lifelong influence on one another. Past research supports an influence between psychopathology of one individual and the psychological functioning of their siblings. Recently this relationship has been examined in the context of borderline personality disorder (BPD), such that siblings of individuals with BPD are at heightened risk of developing psychiatric disorders and engaging in problematic behaviors. Beyond the influence siblings have on one another, there is growing work demonstrating that many siblings of individuals with mental health difficulties face unique challenges in terms of balancing care for themselves and care for their siblings, and yet don’t have resources available for these specific challenges. Methods: The current study utilizes written statements from applications submitted to the Family Connections TM program by siblings of those with emotion regulation (ER) difficulties or BPD. A qualitative analysis is utilized to examine statements written by these sibling applicants, and salient themes are discussed. Results/Conclusion: We hope to clarify the experiences of siblings within these dyads and make a case for increased opportunities for these siblings to access care and support, in order to improve outcomes and support for both siblings.