A sixth person has been charged with murder over the fatal assault of a teenage boy in Sydney’s west.

The 19-year-old woman was arrested in Doonside on Sunday over the group attack on a 16-year old boy at a Doonside home on Wednesday.

The teen was found unresponsive with critical injuries to his head and chest and died in Westmead Hospital on Saturday.

Four boys – two aged 13, one aged 14 and another aged 15 – as well as a 15-year-old girl, have already been charged and remain before the courts.

The 19-year-old woman has been charged with murder, causing grievous bodily harm to a person with intent and detaining in company with intent to gain advantage occasioning actual bodily harm.

She was refused bail to appear at Blacktown Local Court on Monday.