Allen was born Hattie Mae Jimerson in Texas on 8 June 1914 as one of at least 12 children born to Jess and Lizzie Jimerson. She moved to Temple, Texas in 1929, and married Lawrence Allen in 1934. The couple had two daughters.
For her 105th birthday, Allen attended a service in her honour, along with her sister, the Rev. E. J. White, who was also a pastor. By the age of 110, Allen had 18 grandchildren, and numerous great, great-great, and great-great-great grandchildren.
Allen is the oldest known active pastor in the United States, and the second-oldest ecclesiastical person after Sister Francis Piscatella.
Allen’s age was verified by Fabrizio Villatoro and validated by LongeviQuest on 19 June 2024.