Hello Sue,
If you go by what Jean, found and she is a good researcher, then William McNinch, born 1875, Beith, Ayr, his parents were William McNinch, and Jane Craig, they were married 27/Nov/1874. Beith, Ayr.
1881 census Beith, Ayr, Address, Camp House.
McNinch William, Head, Limestone Quarryman, M. age 37 years, M. born West Kilbride, Ayr,
McNinch Jane, Wife, M. age 28 years, F. born Beith, Ayr,
McNinch William, Son, Scholar, age 6 years, M. born Beith, Ayr,
Graig Annie, Sister in Law, ( An Invalid ) U. age 32 years, F. born Beith, Ayr.
William McNinch, the father, his parents were a James McNinch, and a Jean. and both of them were born in Ireland.
Regards,
Jonn.