It appears that this version of the story, about how Ella Wilcox wrote Solitude, is urban legend:

A woman named Ella Wilcox once witnessed a woman sitting quietly by herself sobbing very noticeably in the middle of a train car. At first, Ella was a little bothered by the persistent weeping, but then she noticed another passenger in the car an older gentlemen who was sitting near the rear of the car. He was telling funny stories to the passengers sitting around him. Everybody smiled and chuckled along with the old man. After a while, some of the other passengers in the car started moving. They were getting up from their seats i…