Detectives charged the woman after emergency services were called to a hotel on Mulgoa Road at Wallacia about 4.30am on April 2, following reports of an armed robbery.

Police were told a man - armed with a firearm - entered the business and threatened staff, before stealing cash and a white Holden Commodore parked outside.

Read more: Uppers and downers: Why Keiraville addict handed himself into cops

During the investigation, police were notified of an unrelated incident at Mount Keira on Tuesday April 13.

Detectives from the State Crime Command's Robbery and Serious Crime Squad were told a man was sitting in a parked prime mover on Harry Graham Drive, when he was approached by a man and a woman - allegedly armed with a firearm.

The man was allegedly threatened and detained, before the pair stole his personal items and the truck.

It's alleged the pair pulled over about 600m down the same road and approached a man sitting in a parked Subaru Liberty.

Police will allege in court that man was also threatened with the firearm and forced from the vehicle, before the couple set fire to the prime mover and stole the car.

Following extensive investigations, detectives arrested a 42-year-old man at Gregory Hills last month. He was charged and remains before the courts.

As part of ongoing inquiries, a 25-year-old woman was arrested at a home on Forbes Street, Warwick Farm about 6.30am Wednesday, May 12.

The woman was taken to Liverpool Police Station where she was charged with two counts of robbery while armed with dangerous weapon.

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