According to this article from 2013, she claimed to be 92 years old at the time, which would support a birthdate of c.1921. The Philippines has something known as the Centenarians Act of 2016, which provides a gift of Php 100,000 (around $1,807 USD) to anyone who reaches the age of 100, meaning that there's a big incentive for elderly people to deliberately exaggerate their age late in life in order to receive this reward. 

There's also another woman from her same tribe who claims to be a supercentenarian (like Whang-od, she has the same tribal tattoos all across her arms), but in actuality is likely unsure of her true age: