Bellatrix Black's Education

Bellatrix Black is the eldest daughter of Cygnus and Druella black, she has a three year old sister Andromeda and a one year old sister Narcissa. Bellatrix has turned five and gets to leave the house with her mother for the first time, to start her education.But all does not go well in muggle London. Who is William and what happens to Bella. Find out inside :) Also I do not own HP