Hi Terence Thanks for your message. I passed your info onto my mother who is the researcher of all this.She asked me to send you back the following:
Thanks for info on Mary Kernohan/White.Great help knowing she was a minor when married.Have a possible find on the Familysearch/1880 census
Joseph KERNOHAN Household Male Other Information: Birth Year <1845> Birthplace IRE Age 35 Occupation Works In Rolling M. Marital Status M Race W Head of Household Joseph KERNOHAN Relation Self Father's Birthplace IRE Mother's Birthplace IRE
Source Information: Census Place Weathersfield, Trumbull, Ohio Family History Library Film 1255071 NA Film Number T9-1071 Page Number 416C Name Relation Marital Status Gender Race Age Birthplace Occupation Father's Birthplace Mother's Birthplace Joseph KERNOHANSelfM MaleW 35 IREWorks In Rolling M. IRE IRE Mary KERNOHANWife M Female W 27 IREKeeping HouseIRE IRE James KERNOHANSonS MaleW 55 OH IRE IRE John KERNOHANSonS MaleW 3OH IRE IRE Fannie KERNOHANDauS FemaleW 1OH IRE IRE
From this it would mean Mary was abt 16 when maried and her birth year abt 1853 which ties in with her other siblings.