Johanna was the daughter of Anton Albert Bargmann and Anna Elisabeth Mueller Bargmann. Her parents were German immigrants. On 1 October 1888, Johanna Bargmann and August Seidel were married in Lavaca County, Texas. Their children were Emma Johanna Seidel Franke and Alma Augusta Seidel Krause. On 5 December 1891, August Seidel died.
In 1893, Johanna and John Henry Hillen were married in Texas. The children from this marriage were Willie Henry Hillen, Frieda Hillen, Louis John Hillen, Minnie Martha Hillen Schmidt, Bennie Hillen, Isabella Hillen Turk and Edwin Hillen.