When Margaretta Thomas was born in November 1809, in East Nantmeal Township, Chester, Pennsylvania, United States, her father, William Thomas, was 22 and her mother, Mary Logan, was 15. She married George Washington Bradley on 23 February 1832, in Lebanon, Lebanon, Pennsylvania, United States. They were the parents of at least 5 sons and 3 daughters. She lived in Reading, Berks, Pennsylvania, United States in 1850. She died on 15 May 1875, in Philadelphia Monthly Meeting, Philadelphia, Pennsylvania, United States, at the age of 65, and was buried in Delaware, Pennsylvania, United States.