LOSING MY SISTER, A MEMOIR. By Judy Goldman. John F. Blair. 192 pages. $21.95.

How do we break free from the roles ascribed to us in childhood? Whether you were the “smart” daughter or the “rebellious” son, these labels are hard to peel away, even as we leave our family of origin behind.

For “BrendaandJudy,” two sisters growing up in Rock Hill, S.C., who were so close that their names became one word, shedding those familial roles proved destructive.

Brenda was “the strong one” and Judy was “the sweet one,” and it took the death of their parents for Judy to discard her sweet skin. In her memoir “Losing My Sister,” Judy Goldman tells of her struggle to reconcile with her older sister, while Brenda copes with a terminal cancer diagnosis.

The sisters’ story begins with Judy soaping up in the shower as she notices a lump in her breast. The next morning she calls two people: her doctor and her sister, because Brenda is the person she wants to talk to when something is wrong. “She is practical, clearheaded,” Judy Goldman writes. “She knows what to do. What to think.”

Ironically, Brenda has just discovered a lump in her own breast, and the sisters, who live in Charlotte, are referred to the same surgeon. Judy’s pathology report reveals the tumor is benign, but Brenda’s is malignant.

Shifting gears, the author takes readers back in time to glimpse the sisters’ childhood, and then flashes forward to the diagnoses of their mother’s Alzheimer’s and father’s lung cancer. The situation is both hopeless and overwhelming.

“Watching, in fact, is about all I can do. Watch for fire. Watch for a break in the weather. Watch the disintegration of my mother,” Goldman writes.

The stress of caring for their ailing parents takes a toll on the sisters as they try to divide the responsibilities. “I used to like being told that I was the sweet one and Brenda was the strong one. But I don’t want to hear that now. Yes, I’m having trouble coping. But so is Brenda.”

As Judy moves away from these prescribed roles, her sister stops speaking to her. “Without our parents — without parents the way they are supposed to be (healthy, participating) — my sister and I are totally lost. ... With nobody telling us who we are, everything is up for grabs.”

The sisters attempt therapy and family interventions, and Judy eventually starts writing poetry as a way to process the pain. For anyone with siblings, the complexity of maintaining a healthy relationship, especially while taking care of ailing parents, will resonate.

The author does a solid job of conveying her personal struggle, detailing her attempts to repair her relationship with Brenda, but at moments in the book, I wished the sisters would just kiss and make up.

As Brenda’s cancer worsens, Judy struggles to balance the demands of her immediate family and her career with the ever-increasing likelihood of losing her sister.

“Her approaching death upset our alignment the same way our parents’ approaching deaths did,” Goldman muses.

She struggles to understand their rift right up to the end, wondering if the purpose was to answer that unanswerable question: How can I survive without you? It’s up to each individual to figure it out.

Reviewer Amy Mercer is a writer in Charleston.