Phebe was the daughter of Isaac Washington Pierce, Jr. and Elna Carlson. Elna was the first of Isaac's three wives, the last two of whom were plural wives, as Isaac was a Mormon polygamist.

Phebe grew up in Glenwood, Utah, where she worked in her father's store as a clerk and secretary for her father.

While living in Glenwood, Phebe met Peter Kimball Lemmon, Sr., whom she married December 5, 1883, in St. George, Utah. Since Peter was already married, his marriage to Phebe made him a polygamist.

Although Phebe and Peter were married, Phebe continued living with her parents in Glenwood. She was teaching school at that time. Her parents later moved from Glenwood and Phebe lived in different towns in Sevier and Wayne Counties as she earned her living by teaching.

During that time, Phebe had her first child, Earl Augustus.

In about 1892, Phebe's husband, Peter, along with many other Mormon polygamists, decided to move to Mexico, so they could continue practicing polygamy. Phebe made the move with her mother and other friends. Phebe's father had already taken his other plural family to Mexico; he met Phebe and her mother at Hachita, New Mexico and took them to Mexico.

Eight months after arriving in Mexico, Phebe gave birth to her second son, Wayne Alton, who, unfortunately, died three years later.

While in Colonia Diaz, Mexico, Phebe earned her living by giving music, dressmaking, and needlework lessons. She moved to Colonia Dublan to work in a grocery store owned by her father; after a year, she returned to Colonia Diaz, where she worked for her church in unpaid positions. Five years later she moved to Colonia Juarez to live with her mother, so she could send her son to school. She later returned to Colonia Diaz.

In July, 1912, Phebe, along with all Mormons and other foreigners, fled Mexico because of the growing violence caused by the Mexican revolution. Phebe and her son, Earl, moved to Hachita, New Mexico for a short time. While there, Earl married Ivy Johnson. Phebe and her son and daughter-in-law then moved to Columbus, New Mexico, where they lived until 1916, when they were driven out by an attack by Pancho Villa, a Mexican revolutionary.

Phebe lived the rest of her life with Earl and his wife, Ivy. The combined family lived in many towns, mostly in New Mexico, Texas, and Arizona. Even after Earl's death, Ivy continued caring for Phebe, as well as Ivy's own mother, Lucy Elizabeth Brown Johnson.

Phebe and Lucy Johnson share a joint headstone, both of them called "Mother".