Step-siblings are children born of two different families who have been joined by marriage, defacto or otherwise, of at least one of their respective parents. A male step-sibling is a stepbrother and a female is a stepsister. navigation Jump to search. For the 2018 film, see Step Sisters. For the 2008 film, see Step Brothers.
If Jane and Joe get married, Alexis and Brandon would be stepbrother and stepsister. Full siblings typically refer to each other as simply 'sister' or 'brother.'.