I might point out that anyone who has a problem with Leia remembering her mother solely through Force visions (and indistinct ones at that) must have an equal problem with Luke "recognizing" Yoda's presence on Dagobah.
Quote
LUKE: Still... there's something familiar about this place. I feel like...
STRANGE VOICE: Feel like what?
LUKE: Like we're being watched!
Yoda: This one a long time have I watched. All his life has he looked away...to the future, to the horizon.
Similarly, Leia senses Luke's call, and knows where he is, even though she's never been to the underside of Bespin. The OT clearly establishes these Force visions.
The only reason why I can think that Luke doesn't know his mother's face is because his focus is clearly on his father, as shown early in ANH. He never even seems to think about his mother until talking with Leia in ROTJ. Anakin was very concerned for his mother in TPM, and guess who he has visions of...
"and Owen was Obiwan's brother so it sonly natural that they would have met."
LOL...is that the extent you are going to take it? Now the novelization is canon over ANH as well? Are all the films unneccessary now?