stepsister

A daughter of one’s stepparent.

One’s stepfather’s or stepmother’s daughter by a former marriage.

A daughter of one’s stepfather or stepmother by a former marriage.

The daughter of one’s stepfather or stepmother who is not the daughter of one’s mother and is not the daughter of one’s father.

The stepdaughter of one’s father or mother which is not one’s half-sister.

a sister who has only one parent in common with you