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October 6, 2026

Blue Sisters Book Review: A Sister Is Not a Friend

Coco Mellors, author of Cleopatra and Frankenstein, opens this novel with a family that has lost one of its four daughters. I braced myself for the kind of literary fiction that turns grief into a beautiful, hollow thing. What I found instead was a book asking whether sisterhood survives death, distance, and the lies people tell themselves.

Avery, a recovering heroin addict turned London lawyer, Bonnie, a former boxer working as a bouncer in Los Angeles, and Lucky, a Paris model spiraling through her own addiction, return to New York when the family apartment is about to be sold. A year earlier, their fourth sister, Nicky, died of an overdose tied to pain medication. Three women, three countries, one empty room.

Three Women, Three Countries, One Empty Room

Avery is the one I could not shake. She is the eldest, which in her family means she was never allowed to be young. Mellors writes her as someone who quit heroin and built a whole personality out of control, a wife in London, a career in law, a schedule she can defend. Then Nicky dies and the structure cracks. Avery’s grief looks like guilt, because she was the big sister and being the big sister meant noticing things. She didn’t notice. Or she noticed and looked away. The book does not let her off that hook, and it should not.

Blue Sisters Book Review: A Sister Is Not a Friend

Bonnie, a middle child and former boxer, holds the family’s weather in her body. She is the peacemaker, the one both sisters call, the one who never gets called back. Her chapters were the quietest and the ones I trusted most.

Lucky is twenty-six, famous, and running out of places to hide. Her addiction is active and ugly on the page, and Mellors does not soften it for the reader’s comfort. I found her the hardest sister to love, which I suspect is the point.

The Umbilical Cord and the Friendship Bracelet

The core argument arrives through an image Mellors places near the middle of the novel. A sister is not a friend, the book insists. Comparing a sister to a friend is like comparing an umbilical cord to a friendship bracelet. One was grown inside you. The other you chose.

That distinction is the spine of the whole book. Friendship is optional and renewable. Sisterhood is assigned, permanent, and impossible to resign from. You can move to London. You can stop calling. The cord is still there.

Once I saw that argument, the structure made sense. Three narrators, three countries, three ways of not answering the phone. Each sister believes she is protecting the others by disappearing. Each disappearance reads as abandonment. The novel builds its case through accumulation rather than confrontation, and the effect is a slow tightening rather than a single blow.

The writing is generous and precise in the way it handles small objects. A couch. A cigarette. A garment left in a closet. Mellors uses domestic detail to carry the emotional weight instead of naming it outright. I underlined less than I expected and reread more.

The middle third sags under its own length, and several chapters circle the same realization twice. The romantic subplots feel thinner than the sisterhood, particularly Bonnie’s. The epilogue also ties things a little too neatly for a book that spent 400 pages earning its mess. One quiet ending would have done more than a tidy one.

Grief Has No Calendar

This is not a book for readers who need plot momentum on every page. It is for anyone who has loved a sibling badly and hoped to be forgiven anyway. It is also for readers carrying grief that has outlived its welcome in other people’s attention spans.

If you want a fast thriller, this is not it. If you want a book that sits with you at 2 a.m., it is.

Grief has no calendar, and neither does family. That is the argument Blue Sisters makes, and it makes it without flinching.

Isabella Viora
Written by Isabella Viora