The movie also brought into question whether P.T. Barnum and Jenny Lind had some relationship during the tour

When I read that part, I was not surprised to see this infusion. The truth is that most people connect better to a movie when there is an emotional connection, which is usually a connection between the main character and a Damsel. I believe this is why most movie makers tend to add this part, even when it probably never existed in the main movie.