She has a sister and a brother,
And one other.
He is known as a "half" brother.
The "half" that is not
Her brother,
Comes from being begot
From another,
Her Step-father.

So she has "half" a brother
And a "full" Mother.
And another,
A "Step" father.
That makes her a "half" sister,
To her "half" brother.
Since he is a "half"
And she is a "whole"
That makes one "whole" sister
And brother