My Half-Sister's Sister.

This may or may not be a stupid question, so be nice but I was wondering something about my half-sisters sister. 
My half-sister, Brandy* (*not her real name) & I share a father but not a mother. Her sister Deanna* (*not her real name) is the child of Brandy's mom but she has a different dad than Brandy & I.
So would that make my half-sisters sister my sister or no?