It's a fan edit of Revenge of the Sith that aims to improve the narrative around Anakin's disappointment in and suspicion of the Jedi order, making it a more natural development for him to side with Palpatine. It also has some deleted scenes added in and some other small adjustments.
It's called Labyrinth of Evil, and there are two versions; one where Padme lives, to fit with Leia's lines in Jedi, and one where she dies, like the original.
I've heard good things about the Labyrinth cut. A few years ago I found a fan-edit of the whole prequel trilogy that aims to do the same thing. It edits the three films together for a runtime of just over three hours, and it's a glory to behold. Supposedly it was based on Topher Grace's personal fan edit, but I don't think he ever released his on the internet.
In Return of the Jedi (1983), Luke asks Leia if she remembers her mother. She answers that she remembers her a little and that she died when Leia was very young.
In Revenge of the sith, however, Padme dies immediately after childbirth, so Leia couldn't have had any direct memory of her.