A 22-year-old woman from Sydney's northern beaches has been identified as the final victim to have died in a fiery car crash over the weekend.

Bree Keller, a hairdresser and model from Narrabeen, died after the sports car she was travelling in flipped and burst into flames in the early hours of Saturday morning, her family confirmed to News Corp on Wednesday.

Ms Keller died alongside brothers Steve and Jeff Nasr, aged 39 and 31, when they were unable to escape the burning $200,000 Nissan GT-R R35, which lost control travelling down Goulburn Street at Darling Harbour.

A source who knew the Nasr brothers has also confirmed to Fairfax Media that Ms Keller was the third person in the vehicle who died.