Hello Scotty,
You will find the Mcneice, family living in St. Rollox, Glasgow, on the 1891 census. Mary, is still living with her parents, plus brothers Daniel, and Josuah, and others.
The only marriages for a Tennant, and Mcneice, various spellings are,
1894. Robert Tennant, and Minnie Mcneice, St. Rollox, Glasgow, and 1905 Joseph Tennant, and Minnie Mcneice, Denniston, Glasgow.
Strange two Minnie Mcneice's, marrying Tennants.
Minnie can be a pet name for Minerva, and Mary.
I still reckon your first move is to get her death certificate, this should identify which Tennant she married.
Regards,
Jonn.