The lucky Warrnambool 24-year-old was the envy of every Australian girl on Tuesday when she dined with Prince William in Sydney.

The prestigious Admiralty House luncheon drew an elite crowd of sportsmen, singers and academics - and Kim.

While Delta Goodrem, Michael Clarke and Libby Trickett gushed over the future king, it was Kim who was reserved the best seat at the table.

"I got to sit right next to him," she said.

"We got the seating arrangements just before we went in and everyone was saying 'who is this Kim girl?' - and it was me."

Kim said she got off to a cautious start with her royal date, before adjusting to her special company.

"When we were all standing at the table, ready to sit down, he said that we all looked petrified," she said.

"He told us that he was just as petrified with all of the formal stuff, but he had just learnt how to hide it."

The Brophy House support worker was invited to the private gathering after impressing Governor-General Quentin Bryce in April last year.

Ms Bryce attended the opening of the new community building in Warrnambool and sparked an instant bond with Kim.

"She was really interested in my work with homeless people," Kim said.

"But when I got the call from Canberra last year, I had no idea what they were going to ask."

Kim found her dedication to working with homeless people was an interest shared by the prince.

But when it came to everyday topics, Kim was lost for words.

"He asked what my favourite TV show was and I couldn't answer," she said.

"So instead he just started to guess."

Kim said her next priority was to see the movie Avatar after a positive recommendation from the prince.