Thank you for those references, they lend support to Mary living in Nevins Twp. in 1850. The "obituary" presented on Findagrave appears to be from a newspaper, and the Wabash Valley Obituary Index suggests that it might have come from the _Terre Haute Tribune,_ 24 October 1927, p. 2. A copy should be reviewed to confirm this source.

I also viewed the copy of the marriage license and certificate for Mary and John from the library website (nice database).

Have you obtained a copy of her death certificate? Indiana records after 1920 can be obtained from the state or through Vitalrec.com.