Attack on Titans The soldier from the lower level (Erwin's sister x Eren Yeager)

Theirs is a soldier name (Y/N) Smith. She is like her brother, Erwin, but she is a soldier from a poor level in the walls. (Y/N) and her team of soldiers there can switch to titans, but these people are willing to take the pain from people and the responsibility with the Titan's powers. One day the Scout, Garasiin, and the Military go to the poor level to see what has been happening during the 5 years ago from the attack from in Wall Rose. When Erwin sees something from the corner from his eyes. Everyone turns around and see what was it. The titans that were in front of them were different from the titans that everyone saw, but this ones were looking around the area. But Erwin wasn't that focus on that, he was focused on a girl that sitting on top of a that is a 100-meter black titan and the Titans didn't do anything to that girl nor to the other people that were next to them.