Purna was accompanied by Sadhanapalli Anand Kumar (16), a Class IX student from the Khammam district of Andhra Pradesh, and completed the feat on Sunday morning.
Anand and Purna are both students of Andhra Pradesh Social Welfare Educational Society.
"They climbed Everest at 6 am today after a 52-day long expedition," he said.
"Purna created a record by becoming by youngest girl to climb the Everest," he said.
The duo were selected among about 150 children who were initially chosen for adventure sports as part of the society's initiative to promote excellence in the students of the society, he said.
Twenty of them were sent to a prestigious mountaineering Institute in Darjeeling for training and nine among them were sent on expedition to Indo-China border earlier.
The two students with a higher degree of toughness and endurance were sent to the Everest Expedition in April, he said.
The two students were now returning to the base camp, the official added.