Rhoda Richards (August 8, 1784 - January 17, 1879) makes 30 known wives for Joseph Smith by mid-June of 1843, barely a year before he would be killed. Thirty wives, people! Rhoda was nearly sixty when she married Joseph, but other wives were as young as fourteen. Joseph was having sex with a good number of these plural wives.
Age is no obstacle. Never has been.
Rhoda joined the Church in the mid-1830 via Brigham Young. She moved to Nauvoo in 1842. In Nauvoo she finally met Joseph, and the following year her brother married her to Joseph in an act she seems to have understood as confirming her spot in heaven.
After Joseph was killed Rhoda married her cousin Brigham. She moved to Utah with the Brighamite saints to live out the remainder of her life.