"I am so tired, I just want to go home and sleep," Demelza said.

"I have been doing breakfast radio all morning ... then we did some other interviews so it has been really busy (and) I have had only four hours' sleep."

On Tuesday night, The Illawarra Grammar School Year 11 student won the Australia's Next Top Model title at a live pay TV broadcast from Sydney's Luna Park.

The six judges' votes were split between Demelza and Sydney's Alexandra Girdwood, 21, but the 16-year-old Keiraville beauty won the people's vote.

As a result, she received a host of prizes and opportunities that could pave the way for an international modelling career.

Demelza said she spoke to Ms Girdwood at the show's after party and she was "really great" about finishing runner-up.

"We were both really happy regardless of what the outcome was, I mean we were both so proud that we made it this far," Demelza said.

"And whoever won, we both decided that it was down to fate and it was their time, so we were both supportive of each other."

Nevertheless, Demelza was relieved not to miss out on the top gong.

"I am really glad that I wasn't in that position because I don't know how I would have handled it," she said.

"I think I would have been okay, like I would have understood, but I think would have been a little bit of a mess, I would have been really upset."