Eishier

She can, but they would be the biggest hindrances in MC's pathway to become Batman since they would do everything in their power to prevent it because no parent would want their child to become a suicidal maniac that fights batshit crazy psychopaths on a daily basis.

She changed the entire timeline of the universe they are in, not just MC's. So events that happened will still happen, but with the only difference being that their dates will be different.

just the machine.

Yeah, she is. She is everywhere, all at the same time and not something I made up, it's canon. The death here is her real self, while her avatar's is doing her duty, guiding souls to the afterlife across the DC.