This is what I found:
Lucinda Hughes
in the Tennessee, Marriage Records, 1780-2002
Name: Lucinda Hughes
Gender: Female
Marriage Date: 9 Sep 1866
Marriage Place: Williamson, Tennessee, USA
Spouse: John Mangram
John Mangrum
in the Tennessee, Divorce and Other Records, 1800-1965
Name: John Mangrum
Event Year: 1873
Event Place: Williamson, Tennessee, USA
Spouse: Tennessee Mangrum
Roll Title: Divorce, Probate and Other Records 1800-1899, McL-Man
Roll: B-94
Lucinda could have been expecting at time of divorce, or Malachi Howell was father and they just covered it up by using Lucinda's former married name. Malachi Howell and Lucinda's Marriage cert lists her as Mrs Mangrum.
Hope this helps
Death cert information is only as reliable as the person filling it out. my Dad's own death cerrt has wrong DOB and Stepmother didn't know my Grandfather name.