Ella Reiner was a nursing missionary at the Northern Presbyterian U.S.A. and visited Korea on November 24, 1916, at the age of early 30s. At first, she helped train the nursing department at Severance Hospital in Seoul, but later was assigned to Hall Memorial Hospital in Pyongyang.

Pyongyang Jejung Hospital was developed from a reagent center operated by Wells, a medical missionary of the Northern Presbyterian U.S.A. when she settled in Pyongyang in October 1895, and the hospital building was newly built in October 1906. When the missionary Wells resigned and returned home, the U.S. North Presbyterian Mission and the Northern Methodist were united to jointly take charge of practical affairs and open the hospital. At that time, the working staffs of the missionary department of the Northern Presbyterian U.S.A. were the doctor Bigger and the nurse Reiner. In 1920, the name of the hospital was changed to Hall Memorial Hospital, and in January 1923, Pyongyang Women's Hospital was also united and renamed Pyongyang Union Christian Hospital.

Reiner worked at Pyongyang Jejung Hospital for about a year before Bigger took office and carried out practical work for the establishment of Pyongyang Union Christian Hospital. She moved to Cheongju in 1918 and worked briefly in Siberia as a Red Cross nurse after the outbreak of World War I.

Reiner, who has four years of experience at Severance Hospital and Jejung Hospital in Pyongyang, was appointed as a nurse at Dongsan Christian Hospital in 1919. In the barren environment of the early hospital, she actively handled the ministry, volunteering without sparing sweat and labor. After serving for four years, she resigned as a missionary on February 5, 1923, returned to the United States, and was called by God in California on May 14, 1962.