This is Margaret Godfrey Jarvis Overson and her son Marion Peter Overson. Peter was the youngest of her nine children, born when she was 41 years old, and six years younger than Ross, the next older child.
Peter got his Master's Degree in 1955 from Brigham Young University and wrote his thesis on Joseph J. Daynes, the first organist of the Mormon Tabernacle Choir. (Peter's thesis is quoted in the link to Carol Madsen's article on Daynes from the Ensign.) Peter sang bass in the Mormon Tabernacle Choir from 1951-1958. He returned to Arizona and taught there and took care of Margaret in her final years. Here is another picture of Peter Overson.
Here is his mother's biography from 1954:
Marion Peter Overson, ninth child of Margaret G. Jarvis and Henry Christian Overson, was born at St. Johns, Apache County, Arizona, August 20th, 1920. Marion early showed that he was a different type of person from most of the other children of the family, he was quiet, pleasant and friendly, never quarreling or struggling for his way. He like [sic] to play quietly by himself at drawing, painting, or if other children were with him, at playing house or playing "show," dressing up and acting parts. In school he was agreeable, willing to do what was required of him, but he did not care to take part in the rough, hard games of football and basketball. He got along well with his teachers and liked them and they liked him. He early decided that he wanted to be a teacher, and he chose studies in high school that would prepare him along that line. He loved music, and during his school days played in the band, orchestra, and as an accompanist, on the piano. At home he would practice for hours at a time, and seem [sic] to loose [sic] himself in the playing.
After finishing high school, Marion was determined to continue on at College, tho' to do so he was obliged to get a part time job to help with his expenses. He enrolled at the College at Flagstaff, and was getting along well, when he took "flu" and had to go to the hospital. He worried at loosing [sic] his classes, and as soon as he could possibly be up, went back to school without the Dr.'s consent. He got rheumatic fever, but continued with his lessons and work, tho' it was hard for him to go because of the pain and stiffness in his joints, but he did not want to fail that year. When he came home in June it was found that his heart was much enlarged and in bad condition, and although everything that could be was done for him then, he soon came down with a serious sickness and his life was despaired of for months. Slowly he came back to partial health, but it took six years of treatments by doctors, and living carefully without strenuous exertion before he could resume his studies at the University of Arizona, and still his heart will never be normal.
He finally finished his studies and graduated from the State University at Tucson, receiving a B.A. degree. He has taught in Florida, St. Johns High, St. David High, Tucson, Mesa, and three years in Salt Lake City, and has taken summer work at Provo several years, also one summer in Los Angeles, and now hopes to get his Masters this summer.
He is at present in Salt Lake City, Utah. Still unmarried, (1954).