I wouldn't be too concerned with anything just yet. The more recent picture already shows it's smaller and drying up compared to the original photo.
I had a duck that I had to help hatch due to a shrink wrapping issue and he had the same thing. It eventually shrunk to a very small black tiny bump And wasn't ever an issue.
As far as the broody, I would just keep an eye on everything for now but don't freak out just yet. Like I said, it's pretty early still. I would think after a day or two with her having her chick her instincts will kick in to start showing the chick where to get food and water.