This is an interesting topic, as I have never really thought about it this in-depth.
I always thought that Sarabi was the lioness that says to Kiara, "My, how you've grown.". But now that I look at that lioness she is missing Sarabi's colored paws and her ear rims, as TLP stated. I also noticed that Sarabi is a bit more of a sand color, whereas that lioness is tawny and a darker brown. It could be Sarabi, and they forgot maybe her colors. Disney did get lazy with these two pictures of Kovu because they are replicas and are switched around:
But that's another thing.
I will just dismiss that, because there is proof as Mrs Depp and Regulus said: Sarabi's voice actor died before the production of TLKSP started. I'm just going to go with that.
[quote="FlipMode"]
I mean Mufasa was in the film even though he was dead. So I think it is reasonable to believe Sarabi was "there" one way or another anyway.[/quote]
If Sarabi died, why didn't they show her in the sky with Mufasa? That is just beyond me.