I presume that you have checked the cemetery records at mcnygenealogy.com; the only Buchan there is BUCHAN - Stewart (and one other) [sic] ; he d March 1, 1879 age 78 or 79y; St. Mary’s Hospital; identified by nameplate; interred Oct. 9, 1935 in St. Patrick's lot in Holy Sepulchre Cem.    [8.
However, we (the RGS) did hear last week from the head of Holy Sep:
Stewart & 1 unnamed Buchan
Born: Unknown Died: Unknown Burial: 10/9/1935 Age: 0 NA
Section: Removal from Pinnacle Cemetery
Best guess is that the un named person is Caroline.