Other deaths being examined are those of Alexandra Ross-King, Nathan Tran, Joseph Pham, Callum Brosnan and Joshua Tam, who all died with MDMA in their systems.
The court heard that at 2pm on the day of the festival Ms Nguyen sent text messages to find out where other people she was attending the festival with were getting their drugs from.
'Where u getting caps from. There's no reception there,' she wrote to one friend.
Within an hour she was inside the festival and she purchased 'three caps' from a mutual friend and another three from an unknown man.
She was quickly unsteady on her feet and by 7:45pm she attended the medical tent to seek assistance. There, she fell unconscious and began spasming.
Ms Nguyen was taken to Nepean Hospital, but suffered a cardiac arrest on the trip and died an hour later.
The inquest continues.