When online Newsgroup rumours were running thick and fast during the making of ST VI, and it was revealed that Kim Cattrall had steadfastly refused to play a third incarnation of Saavik, there was supposedly a brief consideration that the new Vulcan character, Valeris (or Eris, or Val'eris), might have been the child of Saavik and Spock, who had hyperaged to adulthood due to the same Genesis effect that had hyperaged Spock in ST III. (I've never seen this rumour reported elsewhere, but I well remember it from the newsgroup printouts of the day. Whether it was fan speculation or an actual leaked conversation from the production, who knows.)
Wow, that's interesting. I never heard that one.
I remember reading online, prior to the movie, that Valeris was originally going to be Saavik but when Robin Curtis was unavailable and they cast yet another different actress, they decided to make it a similar but new Vulcan character in place of Saavik.
Which made Valeris's betrayal shocking to me, as I was essentially imagining her as a proxy Saavik when it finally came out.
Later on I read that early drafts of the script had that character as Saavik but they changed it to Valeris because Roddenberry objected to making Saavik a traitor. (I forget where I read that. It seems like it might have been Shatner's movie memories book, but I might be wrong.)
If that was the reason, then of course they couldn't have said in advance of the movie that was the reason for changing Saavik to Valeris (because it would have given away the plot twist). Imagine how shocking it would have been if they had went for it and made Saavik the villain!