Susan was born May 3, 1825, in Strongstown, Indiana County, Pennsylvania. She was a bright, happy child, quick to take responsibility in the home. She received the same amount of education offered other children in that area at that time.
On October 20, 1836, Susan was baptized with her family by Elder Erastus Snow. From that time on her testimony never wavered, even though she endured untold hardships and persecutions for the Gospel's sake. On September 24, 1839, Susan left with her parents, her sister Sarah, and brothers William and John Albert and journeyed westward to join the Saints in the state of Illinois. They arrived on March 18, 1840. Susan was now a young lady of 15. For a very short time, after gathering at Nauvoo, the Saints enjoyed period of peace from their enemies. In 1841, the Saints, through revelation, were instructed to build a temple, but the mobs stopped them and Susan was living close by when the Prophet Joseph Smith and his brother, Hyrum, were killed on June 27, 1844.
In the Relief Society handbook published in 1931, both Sarah and her daughter, Susan, are listed as members of the Nauvoo Relief Society, which was organized March 17, 1842. Being of marriageable age, Susan was being courted by a fine young man by the name of Henry Mower Jr. He was the son of Henry Mower Sr. and Mary Amick. He and his family were also converts to Mormonism and had joined the Saints in Nauvoo. This young couple were married on December 11, 1845. She was 20 and he was 21. The temple had been rushed to completion so the sacred ordinances for which it was built could be performed therein. It was February 3,1846,when Henry and Susan received their own endowments in the Nauvoo Temple.
Soon after this, the great move started from their City Beautiful. The Saints took what little they could with them and crossed the ice-clogged Mississippi River into Iowa where the homeless refugees gathered in temporary camps. One such camp was Council Bluffs or Kanesville, in Pottawattomie County, Iowa. It was here that Susan and Henry lived the next two years. It was here also that Susan gave birth to her first child, William Henry, on September 24, 1846. The conditions under which this baby was born were so deplorable that the little thing died the next day. By the time their second son, John Albert, was born on August 3, 1847, things were some better.
Records show that Henry, Susan, and their one-year-old son, John Albert, along with her parents and other family members were assigned to travel in Silas Richards' Company. This was a large group which left Kanesville on July 10, 1849 and arrived in the Salt Lake Valley on October 12, 1849. They were happy indeed to reach their destination. They drove immediately to Pioneer Square which was the stopping place for the emigrants. The houses of the fort furnished a first home for many new arrivals, and this was where Henry and Susan spent their first winter. As soon as possible, they moved out into the city.