What role did Kelley Mack play in Chicago Med and 9‑1‑1?

Kelley Mack (born Kelley Lynne Klebenow; July 10, 1992 – August 2, 2025) was a multitalented American actress, producer, and voice-over artist whose thoughtful performances captivated both audiences and critics. While she is best known for her recurring role as Addy in The Walking Dead, her guest appearances on medical drama Chicago Med and procedural series 9‑1‑1 demonstrated her emotional range and deep commitment to nuanced storytelling. Mack’s career spanned over thirty acting credits and solidified her as a creative force across film, television, and voice work.

Penelope Jacobs – Chicago Med (Season 8, Episode 6)

Mack guest-starred as Penelope Jacobs in the Season 8 episode titled “Mama Said There Would Be Days Like This.” In this emotionally charged narrative, Penelope arrives at the emergency department grappling with postpartum emotional instability. Initially suspected of postpartum depression, doctors ultimately determine she is suffering from Bell’s Palsy—a neurological condition that impaired her facial movement and disrupted her emotional expression, leading to misinterpretations by medical staff.

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Through her performance, Mack humanized a condition rarely explored on mainstream television, allowing viewers to witness the complexity of neurological disorders and maternal mental health. Her portrayal conveyed vulnerability, confusion, and resilience—making Penelope’s journey one of the episode’s most memorable and empathetic storylines.

Sydney – 9‑1‑1 (Season 3, Episode 17 “Powerless”)

In 9‑1‑1, Mack plays Sydney, a pregnant woman who becomes a critical part of an unfolding disaster scenario in Episode 17, titled “Powerless.” When a sudden blackout cripples emergency systems across Los Angeles, Sydney goes into labor during the crisis. Emergency responders must navigate failing infrastructure—elevators, blocked corridors, and chaotic crowds—to safely deliver her baby.

Though brief, Mack’s portrayal encapsulates panic, courage, and maternal strength under pressure. Her emotional authenticity grounded the high-stakes drama in real human experience, reinforcing 9‑1‑1’s reputation for tension while reminding viewers of the personal stories behind each emergency.

Broader film and television contributions

Beyond these guest roles, Mack built a diverse and impressive career. She starred as Addy in five episodes of The Walking Dead Season 9, earning acclaim for her portrayal of a young survivor captured by the Whisperers. On the film front, her notable roles include Alice in the psychological thriller Broadcast Signal Intrusion (2021) and Wilda in Delicate Arch (2024). Her final film, Universal (2025), premiered shortly before her death—she played Ricky and served as an executive producer.

Mack’s early career roots trace back to her debut in the award-winning short film The Elephant Garden (2008), where she received the Tisch School Acting Award and a Student Visionary Award at the Tribeca Film Festival. She later honed her skills behind the camera—writing, directing, editing, and producing shorts such as Positive (2015) and A Knock at the Door (2016), winning accolades at festivals like Atlanta Horror Film Festival and FilmQuest. Her creative versatility extended to voice work, including voicing Hailee Steinfeld’s Gwen Stacy in Spider-Man: Into the Spider-Verse campaigns.

Personal Life and Legacy

Born in Cincinnati, Mack graduated from Hinsdale Central High School (2010) and earned a degree in cinematography from Chapman University’s Dodge College of Film (2014). Her early passion for storytelling was sparked by a childhood gift of a mini video camera. In early 2025, she was diagnosed with diffuse midline glioma, a rare and aggressive central nervous system tumor. She shared her journey via public updates, detailing her rehabilitation milestones, including relearning to walk with a wheelchair and a walker. Mack passed away peacefully on August 2, 2025, surrounded by family in Cincinnati. Tributes described her as a “bright, fervent light,” and remembrance services were held in Ohio (August 16) and later in Los Angeles.

Conclusion

Kelley Mack’s roles in Chicago Med and 9‑1‑1, though limited in screen time, showcase her exceptional ability to convey emotional realism and depth. Whether portraying a mother weakened by neurological misdiagnosis or a pregnant woman in dire circumstances, she brought authenticity and dignity to each character. Across film and television, Mack’s legacy is defined by empathy, creative ambition, and a commitment to representing difficult truths with grace. Her untimely passing leaves a void but also cements her as a beacon of talent and humanity in contemporary storytelling.