This is like a sore tooth and I just couldn't leave it alone - Lillie Nancy Blezen (aka Belzen-1) may actually be two people that have been confused. Most of my sources right now are from Ancestry and I don't know if that would be helpful at the moment. If you would like me to continue, I will search on Familysearch.org for others. Here goes-
Joseph M Aday married an Necey Belzen in 1886 in Williamson County, TX
She is on the 1900 census as Nely Aday in Georgetown, Williamson, TX with Joseph M and 5 children and a boarder.
The findagrave picture for the grave marker could be Mrs Nely/Necy Aday who died in 1903. Williamson County TX
The Lillie on the 1910 census looks to be a remarriage (m2- for JM as well). Also it notes that Lillie has had 2 children; she and JM have only been married 5 years; the children in the household are over 12; there is a 20 yo male with the surname of Murray. Travis County TX
Lillie remarried after JM Aday passed. It looks like she married a Robert Leigh (1920 census). Nueces County TX
Which leads to a findagrave memorial for Lillie Zimmerman Leigh (wife of RB Murphy) Williamson County TX
"Find A Grave Index," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:QVVF-VCVB : accessed 7 April 2016), Lillie Zimmermann Leigh Murray, 1945; Burial, Round Rock, Williamson, Texas, United States of America, Round Rock Cemetery; citing record ID 15842295, Find a Grave, http://www.findagrave.com.
It's midnight in Texas so sweet dreams, y'all