In the 1900 census, Irene said she had 8 children, all living, so there must have been 5 more children born ca 1884-1896.
Irene Ellen SWITZER, b 14 Sep 1867 Hicksville, OH, d 18 Jul 1952 in rural Farmer Township. For residence, typed in but lined out, was "one mile northeast of Six Corners." Mrs. Edith SMITH was the informant and she said Irene's father was Henry GILBERT and her mother's maiden name was Viana SISCO. Irene was buried 21 Jul 1952 in Six Corners Cemetery.
Irene was a widow when she died but I can't find an Ohio death cert (1920-30) for David.
Check with the Defiance Public Library for David and/or Irene's obit which may mention all of the children. The Defiance Records Center has marriage info, too. See http://www.rootsweb.ancestry.com/~ohdefian/index.htmlhttp://www.rootsweb.ancestry.com/~ohdefian/index.html for addresses for the library and the records center.