Maddy’s beloved nurse; Carla’s job is to spend eight hours per day monitoring Maddy’s vital signs. Carla has a 17-year-old daughter named Rosa, whom she dotes on and loves dearly. She’s been caring for Maddy since Maddy was a toddler and over the years, Carla and Maddy have developed a genuinely close, caring, and trusting relationship. Unlike Mom, Carla recognizes that it’s normal for a teen Maddy’s age to be interested in boys and in the world around her, and she’s adamant that love and loss are a part of life and aren’t deadly. Because of this, she allows Maddy and Olly to see each other in person. Though she makes it very clear that they’re not allowed to touch each other, she also doesn’t supervise them or enforce this rule. When Mom discovers Carla’s leniency, she fires Carla and insists to Maddy that Carla was supposed to keep Maddy safe from everything, both health-wise and in terms of heartache. Due to their close relationship, Maddy insists on visiting Carla before she and Olly go to Hawaii. Carla understands that Maddy is lying about having pills from Canada, but she offers Maddy a way to think through her choice when she tells Maddy about her own decision to leave Mexico as a young woman. It simultaneously gave her the much better life she lives now, while also cutting her off from her family and her heritage in a way that pains her. She suggests that regretting is a part of living. After Maddy returns home and recovers from the serious illness she comes down with in Hawaii, Carla returns to care for her. When Maddy discovers that her SCID diagnosis may be incorrect, Carla is instrumental in helping Maddy find a doctor, undergo testing, and uncover the truth. Carla ultimately leaves Maddy to find another job, as she recognizes that Maddy doesn’t need her anymore.