Complex sentence: A prostitute and police informant, Shirley Margaret Brifman (usually known as Marge), ran a brothel in a flat at Potts Point, with up to fifteen girls.
Split into simpler sentences: A prostitute and police informant, Shirley Margaret Brifman (usually known as Marge), was a police informant. She ran a brothel in a flat at Potts Point with up to fifteen girls.