A sister is a little bit of childhood that can never be lost.

The line frames sisterhood as a living repository of shared early life: a sister carries memories, habits, and affections formed in childhood, and those bonds persist even as people age and circumstances change. Calling a sister “a little bit of childhood” suggests that family relationships can function as emotional time capsules—preserving a sense of origin, continuity, and identity when other parts of childhood (places, friends, routines) inevitably disappear. The final clause, “can never be lost,” emphasizes durability: even estrangement, distance, or time cannot fully erase the formative imprint of growing up together, making sisterhood a uniquely enduring form of companionship and witness.