Pandelela was born in (Kampung) Kupuo Jugan, a Bidayuh village in Bau, Sarawak to Hartini Lamim and Pamg Joheng. She is of Bidayuh ethnicity, a Bumiputera native to the Malaysian state of Sarawak. She is the second of four siblings. At the age of seven she was selected as a state diver and continued her training at the Bukit Jalil Sports School. She graduated from University of Malaya in 2018, majoring in Sports Management Science.
In June 2018, Pandelela and six other divers were caught in controversy after a video showed them partying and drinking alcohol during a training camp in Guangzhou, China. The video was allegedly recorded on the eve of Chinese New Year day. Following the incident, the Amateur Swimming Union of Malaysia (ASUM) suspended the allowances of the seven national divers with immediate effect with more disciplinary action set to follow. Pandelela and the six other divers apologised publicly and promised the incident will not be repeated. ASUM announced later that no further action will be taken to the seven divers as the divers have already expressed remorse for their actions.