Go to Findagrave.com
Search for Sulphur Springs Cemetery in Vigo County, IN
Search for surname MACE

You will find tombstone for Carl and Gladys, and also one for Marian E. She died at age 16.

Can't explain her omission from the obits, but she died in 1944. Perhaps those who wrote the obits never knew her, or had faulty memories.

Robert in Arkansas
No relation - not researching
Just trying to help out