Rebecca Lukens had sole proprietorship of the Brandywine Iron Works from 1825 until 1840. Her brother-in-law, Solomon Lukens, retired to a farm near Ercildoun in 1837, and married a Quaker poetess, Susan Wilson. Another brother-in-law, Joseph Bailey, husband of Dr. Lukens’ sister, Martha, joined the firm of Rebecca W. Lukens & Co. in 1840, remaining until 1843, when he withdrew to purchase and operate the Pine Iron Works near Pottstown.

Rebecca's family also expanded. In October 1841, Abram Gibbons, Jr. married Rebecca’s eldest daughter, Martha. He joined the business in 1842 and became a full partner by 1844. Gibbons was an accomplished businessman and his capable management allowed Rebecca to decrease her involvement and then become a silent partner in 1847. By that time, 53-year-old Rebecca had run the operation for 22 years. For two years, the firm was styled A. Gibbons, Jr. & Co., with Rebecca retaining basic control and ownership of the mill property, and Gibbons conducting business affairs.

In 1847, Rebecca's daughter Isabella married Dr. Charles Huston, a Philadelphia physician. Dr. Huston, like Dr. Lukens before him, abandoned medicine for the iron industry. Despite medical education and training, Dr. Huston found the city unsuited to his health. He moved to Coatesville and became a partner in a freight handling business with George W. P. Coates. He joined the Lukens-Gibbons partnership in 1849 and the firm was named Gibbons & Huston, as Rebecca became a silent partner and turned over management of the business to her capable sons-in-laws, Abram Gibbons and Charles Huston.