I realize that I should defer to the author of the postcard because (1) the end of the street is pretty fuzzy and (2) I didn’t live in Duluth in 1905, but I’m just going to go ahead and call out Gertrude anyway and say that I think she guessed wrong. As fuzzy as they are, it seems that there are curved roofs and towers visible above the X and Craggencroft did not have those. It looks like Craggencroft was also set back pretty far from the street. What Gertrude marked seems to match better with the Glen Avon waiting station and the original Glen Avon Presbyterian Church (which was directly across the street from the current church).

That would put the streetcar (which probably isn’t there at all, since the shadows below the car suggest it is a superimposed element of the composite image along with bears) directly alongside Craggencroft, with the fence of the property visible on the right side of the image. 

Or maybe Gertrude had just taken a walk along Woodland Avenue before she bought the postcard and knew exactly what was talking about (although she herself did admit she was only guessing).