Han skated to 12th place out of 36 competitors in the preliminary round to win her way into the main draw, then placed 23rd in the short program.
In the free skate, the 15-year-old produced a personal best 68.70 points for 20th position, lifting her two places higher on the overall standings.
Her total score of 106.98 points was just 0.22 of a point below her personal best result.
Han, a year 10 student who divides her time between Redding, Connecticut, and the Melbourne suburb of Port Melbourne, was pleased with her performance in her first major international event.
"I felt that there were definite highs and lows in all three performances," Han said, "but no matter how well I skate I know that there are always areas in which I could improve."
"However, I was very happy with my spins, steps, and skating skills. I was also quite pleased with how I handled skating for such as large audience, as I have never done something like that before."
"I have never seen a competition of this calibre before so I had no idea what to expect. My goals were to skate my best, participate in the competition and enjoy the experience."
"I was also happy that I executed my three jump combination in the preliminary round as well as in the long program. This was also one of the first times I have tried triple loop and competition and I was happy that I was able to compete with the new element."
"Participating and competing in Junior Worlds was really a fantastic experience. I hope to carry that experience on into next season, as I hope to continue to represent Australia internationally."
Russia's Adelina Sotnikova skated to the gold medal with teammate Elizaveta Tuktamisheva taking the silver medal. The 2010 silver medalist Agnes Zawadzki from the US claimed the bronze.
In the boys'event, Brendan Kerry placed 17th in the preliminary round, missing a berth in the main event, while Kimberley Hew-Low and Cameron Hemmert also failed to make it through in the ice dancing.