This is the tombstone of Maria (Betzel) Herzog, located in row 5 of Zion Lutheran Cemetery, Chattanooga, Mercer County, Ohio. The marker is inscribed:
G. Friedrich Herzog
Gest. 2 Mai, 1903
Ater 74 J 11 M 16 T
Translation: Maria, wife of G. Friedrich Herzog, died 2 May 1903, aged 74 years, 11 months, 16 days.
Maria was born 17 May 1828, as calculated from the information on her tombstone. Her church death and burial record indicates she was 75 years and about 2 months old. She was born in Bavaria, according to the 1880 census. 
Maria Betzel married Friedrich Herzog on 27 January 1872 in Mercer County, Ohio. They were married by Lutheran pastor L. “Lerr.” 
This was Friedrich’s second marriage. Friedrich married Catharine Kuhn on 15 April 1852. Catharine died 9 December 1871 at the age of 44 years, 9 months, and a few days. She has two tombstones in Zion Chatt’s cemetery, an older one and a newer one. Both tombstones are side by side and the newer one is situated south of her husband’s stone.
In 1880 Friedrich, 55, and his second wife Maria, 52, lived in Liberty Township, where Friedrich was a retired farmer. There were no children in the household. This record indicates they were both born in Bavaria. 
It appears that Friedrich and Maria never had any children.
Georg Friedrich Herzog died of a stroke on 21 July 1901, at the age of 76 years, 4 months, and 25 days.
His widow Maria (Betzel) Herzog died a couple years later, on 2 May 1903, and was buried on the 4th. She is buried on the north side of Friedrich and Friedrich’s first wife Catharine is buried south of him.
Other than that, I was not able to find any more information about Maria. She would have been about 44 years old when she married Friedrich Herzog. Was Betzel her maiden name? Or was her marriage to Friedrich Herzog her second marriage, which would make Betzel her married name?
 1880 U.S. Census, Liberty, Mercer, Ohio, ED 188, p.471B, dwelling 15, family 16, Frederick Hartsog; Ancestry.com (accessed 5 Feb 2017); NARA microfilm T9, roll 1048.
 “Ohio, County Marriages, 1789-2013,” database with images, FamilySearch.org (accessed 5 Feb 2017), Frederick Herzog and Mary Betzel, 27 Jan 1872; Mercer County Marriages, Vol. 3, p.301; FHL microfilm 914956.