Gertrude Tackett has been a very hard woman to trace indeed!I've been searching 37 years now and she remains elusive.
The Moore Family Tree on Ancestry.com is by a cousin of mine who joined the search a couple of years ago.
I've never seen any source document for a 1837 birth or 1920 death (I estimate ca. 1856 for her birth based on her first child's birth date).I don't think Gertrude was a daughter of O. H. P. Tackett - I think she either married one of his sons or had a child(ren) by one of them.BTW - OHP Tackett is also found in the 1880 Fed Census in Holmes Co., as well as the 1860 Slave schedule, IRS Tax Assesments and Civil War Records.I also have his wife as Elmira Jobe, not Tobe.
The midle name for Yovel was from a note written by my grandmother, Ruth Moore, during an oral interview with Porter Yelverton (5th son of Laura Belle Tackett Yelverton and grandson of Gertrude) in 1988 in Alabama.He gave her name (or she wrote it down) as 'Gertrue'.Only 4 children were listed - Gertrude Elizabeth, b. 1876, Laura Belle, b. 1877, Julian Dye, b. 1880, and Tovel Boswell, b. 1882.I was not aware of a fifth child, but have seen Gladys Dye in the 1900 Cen in Texas.
Family tradition says Ms. Gertrude was born in Georgia and was part Cherokee.
I can send you a copy of the letter from W. P. (Walter Perdue) Tackett and other info if that will help in your search. Please contact me as I'd like to collaberate more. Thanks, Ron