There are no Williston marriages with a wife named 'Elizabeth' on the BC archives, no Elizabeth Williston deaths, and only one family of Williston living in BC in 1901:
John G. Williston, widower, b. Sep6 1867, Ontario, with 'mother' (could be mother-in-law?) Margaret Currie, b. 23 April 1852, Margaret's daughter Vina Currie, b. 1876, and John's children Florence, b. 1898 (b. US) and Cecile C, b. 1897.