Nepal's astrologers are reviewing horoscopes to find the replacement for the current goddess, who is 11.
"If we don't change her now, we'll have to wait until next year which could be late," said Deepak Bahadur Pandey, a senior official at the state-run Trust Corporation that oversees cultural affairs in the politically turbulent Himalayan nation.
"If the girl starts menstruating while serving as kumari, it is considered inauspicious."
For hundreds of years, living goddesses have been held sacred in Nepal and their blessings have been sought by officials and others seeking good fortune.
Many campaigners believe the practice is outdated and harmful to the young girls, who must be willing to give up a normal childhood, live a cloistered life and offer occasional blessings. The contract is terminated when they reach puberty. There are more than a dozen kumari in Nepal, but it is the Kathmandu or chief Kumari that is the most important goddess.
The abolition of the 240-year-old monarchy earlier this year and the declaration of Nepal as a republic has complicated the selection process this time.
Traditionally, Nepal's king received the Kumari's annual blessing and astrologers would look for a child whose horoscope matched that of the monarch. Now officials have to find someone else to fill the king's shoes.
Chunda Bajracharya, a professor of cultural studies at Tribhuvan University in Kathmandu, said the republican status of Nepal was no excuse to drop centuries-old traditions. "We cannot end these traditions just because there is no king."
For the Kathmandu Kumari, cut off from the outside world, carried everywhere and not allowed outside her temple, life is not easy. Yet many families still put forward their daughters for the role, both for the supposed honour and for the modest compensation given to the family.
In recent years campaigners have pointed out the detrimental effects of the tradition and former kumaris have told of their difficulty in adjusting to normal life once their contracts have been terminated.
Three years ago, Pundevi Maharjan, a human rights lawyer in Kathmandu, filed a lawsuit claiming the children's rights were being abused and demanding reform. "I said exploitation and discrimination has been going on. This should be eliminated," she said last year. "We don't want to end the tradition but we have to change for the protection of the culture."
But Mr Pandey said the secret selection process was already well under way for a new kumari. The girl must have perfect eyes, teeth, hair and not even the smallest scratch on her skin.
Nepal held elections in April and former rebel Maoists are now poised to form the country's new government.
Having campaigned stridently against the discrimination of the Nepalese Hindu caste system and for the establishment of a republic, it is unclear whether they will allow the kumari tradition to continue.
Another person already out of a job is the former royal priest, Madhab Bhattarai. Perhaps not surprisingly, he regrets the abolition of the increasingly unpopular monarchy.
"For centuries Nepal has remained socially harmonious, despite being a multi-ethnic, multi-lingual and multi-faith country," he said. "It was the king who was a central point of unity."