Here is Charles marriage record; Same parents:
"Wisconsin, County Marriages, 1836-1911," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:XRG3-WMM : 3 June 2016), Charles C. Slack and Elsie May Warner, 06 Sep 1904; citing Stevens Point, Portage, Wisconsin, United States, Wisconsin Historical Society, Madison; FHL microfilm 1,275,499.
Name Charles C. Slack
Male White Birthplace Buena Vista, Portage, Wi
Father Perry R. Slack
Mother Jennie M. Crary Slack
Marriage 06 Sep 1904 Stevens Point, Portage, Wisconsin, United States
Spouse Elsie May Warner
Female White Birthplace Eidsbold, Clark, WI
Father S.E. Warner
Mother' Mary Ann Thompson Warner