Myrtle Ngit Ung Kwock Aiu was born on October 12, 1916, in Honolulu, Hawaii, the first of eight children of Chinese parents Chong Kai Kwock and Alice Lo Chee Chang. Her birth name was Ngit Ung, but one of the nurses suggested they call her Myrtle to make it easier for English-speakers. At age two, the family moved to Hanapepe, Kauai, where Myrtle attended the Eleele Grammar School through the eighth grade; at this point, she decided to stay home to help out in the family's dry goods store, while teaching herself to type.

On June 28, 1937, she married William Aiu in the Lihue Union Church. The couple welcomed twin girls, Jean Kalei and Joan Kulei, on May 3, 1941. In 1947, Myrtle bought her first Bible and began began a search for a church to join. Within a few months, a senior missionary couple from the Church of Jesus Christ of Latter-day Saints came to Myrtle's door and introduced her to their church. Myrtle was baptized on March 25, 1948, at Kapaa Beach by Elder Oather Roper. Her daughter Jean was baptized on April 6, 1956.

Myrtle served in many Latter-day Saint church callings through the years, including Primary president, Sunday School and Young Women's teachers, Relief Society president, and Stake Relief Society counselor. She also ran a two-room motel connected to her home for 14 years, from 1961 to 1975, and volunteered extensively in the community (making flower arrangements for the library, working in the museum, helping with cancer and medical testing drives, sewing cushions for a community foster home, fundraisers, office work, etc.)

Myrtle died on November 25, 2010, in Honolulu, Hawaii.