Forum:SH:Leia isn't Luke's sister?

I just read this: "The focus would be on Luke Skywalker's journey to becoming the premier Jedi knight, with Luke's sister (who was not Leia) appearing in Episode VIII, and the first appearance of the Emperor, and Luke's ultimate confrontation with him, in Episode IX (a storyline as planned pre-1980, according to A New Hope and The Empire Strikes Back producer Gary Kurtz)"

http://en.wikipedia.org/wiki/Star_Wars_sequel_trilogy

From the star wars trilogy sequel... Is that true?