Police found the body of Ms D'Addario, 35, in the boot of a car on the NSW far south coast on Wednesday night, after family reported her and Canberra man Josaia (Joey) Vosikata, 27, missing on Monday.

Josaia Vosikata, of Bruce, appeared before Magistrate Beth Campbell in the ACT Magistrates Court on Friday afternoon after being extradited from NSW earlier in the day. He was formally charged withthe murder of Daniela.

Close friend Chris Reid and his wife, Kathryn, became friends with Ms D'Addario six years ago when she moved next door to their house in the Canberra suburb of Palmerston.

Mr Reid, who now lives in Brisbane, said Ms D'Addario had been dating Mr Vosikata on and off the past few months before she found out he had a wife and children in Fiji.

"His parents were in the same unit block as she was.

"Daniela found out he had a wife and kids back in Fiji ... probably a month ago. When Daniela found out, at this stage, this bloke was living in Daniela's unit, not paying any rent and sending money back to his wife and kids in Fiji.

"She obviously flipped and broke up with him. For whatever reason, they got back together."

Mr Reid said he and his wife "got a bad vibe" from talking to Ms D'Addario about the relationship.

His wife and Ms D'Addario kept in touch regularly and last spoke a week ago.

Mr Reid described the 35-year-old Ms D'Addario, who worked as a public servant in Canberra and previously taught at Canberra High School, as "a beautiful girl".

"She was very caring and very intelligent and always wanting to help."