It is believed Ms Parsons and Mr Deakin-White were engaged and Ms Parsons, a former Koonung Secondary College student, had visited Melbourne as recently as January.
Mr Deakin-White was a Royal Opera House designer and the pair had been together for at least six years, according to The Sun newspaper.
Neighbours described him as «really nice» and always willing to help out at the block of flats where the couple lived.
One neighbour described Ms Parsons as a «lovely and positive» woman.
Asad Samee, 21, told The Evening Standard: «Amy was very friendly, the sort of person who would always give you a smile.
«They were a really nice couple; just lovely, happy people. When I saw the police and ambulance I knew something was wrong. It is horrifying.»
Numerous photos on Ms Parson’s Facebook page show the couple celebrating Christmas and other special occasions with family and friends.
Friends in Melbourne were struggling to comprehend the tragic news on Monday.
«She was one of the best people you could meet,» said one friend, who was too upset to speak at length.
«I just had lunch with her in January – she was back in Melbourne. She was just a very good person.»
Ms Parsons’ LinkedIn profile suggests she had been working in London for the past seven years as a personal assistant at financial services firm, Old Mutual.
In a statement, London’s Metropolitan Police said officers went to the couple’s Crowder Street flat on Friday «following concerns for the welfare of a female resident».
«Officers attended with the London Ambulance Service. A 35-year-old woman was discovered. She was pronounced dead at the scene.
«Roderick Deakin-White … was arrested on suspicion of murder the same day. He was charged on Sunday.
«At this stage, no other person is being sought in connection with this incident.»
The cause of death has not been confirmed, but a post-mortem is expected to conducted this week, police said.
The Department of Foreign Affairs and Trade said consular officials are providing assistance to Ms Parsons’ family.
Zach is a breaking news reporter for The Age.