A young woman, who plunged to her death from a hotel balcony in Cronulla, has been described as a beautiful, happy soul.

The 21-year-old was heard arguing with her boyfriend just moments before she fell from their tenth floor balcony.

Police say it's too early to determine what led to the tragedy.

Eden Hall and her boyfriend were relaxing in Cronulla on their summer holiday.

"They were in the area, they were enjoying the seaside environment," Detective Superintendent Greg Antonjuk said.

After deciding to extend their stay by a night, they had dinner at a popular Thai restaurant.

Police say they had been drinking, but there was no indication of the tragedy about to unfold.

One of the waitresses at the restaurant said everything seemed normal between the pair.

Just 50 metres away from where they dined, at the Rydges Hotel, Eden and her 27-year-old boyfriend started arguing.

She then plunged from their tenth floor balcony onto the building's second level pool deck.

The 21-year-old survived the impact but died six hours later during surgery in St George Hospital.

Police say her boyfriend's story is stacking-up.

"There was a disagreement between them but there is nothing stronger than that that at this point of time," Detective Superintendent Greg Antonjuk said.

"It's consistent with as I believe with a lot of other versions that other people have told us."

While police stopped short of describing the young woman's death as suspicious, they spent the day examining CCTV footage, trying to piece together the couple's movements in the hours leading up to the tragedy.

A post mortem is expected to confirm that alcohol was a factor.