Yours is an excellent guess, but incorrect. Thanks for introducing me to someone I was unfamiliar with before this.
One note. Tarbell, like several other American Progressives, saw in Mussolini a positive figure who used the power of the state to improve the life of his people. While I can't say that Tarbell completely lost her admiration for the pre-war Mussolini, I think her eyes were opened to the dangers of fascism with the rise of Hitler, which is, in my opinion, why she declined to interview him.