Documentary probes the case of Rosemary Ndlovu, who killed six people close to her
		
	 
	
		
		Female killers usually do so for three reasons – psychopathy, greed and because they’re abused – but there is gender bias even in murder
		
	 
	
		
		Rosemary Ndlovu and co-accussed Nomsa Mudau make second appearance in court amid fresh charges of conspiracy to commit murder