step-siblings

Step-siblings are individuals who become related through the marriage of their respective parents, but they are not biologically related. For example, if a person's parent marries someone who has a child from a previous relationship, that child becomes their step-sibling. They share no blood ties but are part of each other’s family due to the new marriage. Step-siblings may grow up together or know each other at different times, and their relationship is defined by the family structure created through the adults’ marriage or partnership.