Step 1 : Introduction to the question "how are sonia and bianca related"
...Sonia Fowler (also Branning and Jackson) is a fictional character from the BBC soap opera, ..... Patsy Palmer, who returned to EastEnders as Sonia's sister Bianca. Among them were the Jackson family: mother Carol (Lindsey Coulson), her four children, Bianca (Patsy Palmer), Robbie (Dean Gaffney), Sonia (Natalie Cassidy), and Billie (Devon Anderson), as well as Carol's partner Alan Jackson (Howard Antony). ... Cassidy was 10 years old when she joined the soap as Sonia.