Good thoughts there! I agree that Peter or Edmund wouldn't have responded to Aslan's death in the same way as either of the girls, and having one or more of them there would have changed the dynamics of the story. However, I've just been thinking that there's perhaps another reason why Lewis chose specifically to have Lucy and Susan present at this point in the narrative.

Although he was very clear that Narnia is not allegorical — that is, there's not a one-to-one correspondence between the characters and events in the Chronicles and the people and events in the Bible or in Christian history — he did intend for readers to be able to find things in the Narnia stories that remind us of Christianity as we know it in our world. So while Aslan's death and resurrection in LWW aren't meant to be read as a "rewrite" of Jesus' death and resurrection in the Gospels, there are definitely echoes and parallels there. And all four of the Gospels make the point that of all Jesus' followers, only a small group of women (plus, solely in John's Gospel, the unnamed "disciple whom Jesus loved") stayed by him throughout his crucifixion and then came back the day after the Sabbath to anoint his body in the tomb — only to be told "He is risen!" and to be the first people to see him after his resurrection.

So it makes sense to me that in Narnia, when the same Saviour, in a different shape and under a different name, dies and rises to save another world as he did ours, it's again his female followers — this time, two young girls — who turn out to be brave and loving enough to stay with him throughout that ordeal and to see him come back from the dead. Again, that doesn't mean Susan and Lucy are meant to "be" Mary Magdalene or any of the other Biblical women, but they do hint at the story from our own world that Lewis wants us (ultimately!) to remember and think about more deeply. 

Posted by: @kingedthejust

I think if Edmund were with Lucy he would not know how to react. He would've been extremely traumatized and pained seeing Aslan taking his place on the stone table.

I think this is a very good point, and the reason it certainly couldn't have been Edmund. While Lewis certainly was never one to underestimate his young readers, I think this would have been too dark of a place for the story to go. While obviously any of the Pevensies would have been traumatized by witnessing Aslan's death, Edmund would have been especially so.

On a recent reread of LWW, it struck me just how horrifying things would have been if Aslan had not taken Edmund's place. To kill a child in the way Aslan is killed... it would never happen in the Narnia books, but in the Narnia universe it's what was planned for Edmund, and he would have known that. He would have seen exactly what had been in store for him. The guilt associated with that very well might have broken the poor boy. I don't think Lewis could have effectively navigated that type of trauma and kept the book appropriate for children. 

Although the fanfiction writers among us might be able to explore that idea well in the right context.

As a side point, I think it's interesting that the question was framed as who would accompany Lucy, rather than if who would go instead of Lucy and Susan. It just doesn't make sense to imagine this scene without Lucy being present there, maybe because of her unwavering faith in Aslan.

Posted by: @eagle-scout

 

As a side point, I think it's interesting that the question was framed as who would accompany Lucy, rather than if who would go instead of Lucy and Susan. It just doesn't make sense to imagine this scene without Lucy being present there, maybe because of her unwavering faith in Aslan.

I can't imagine Lucy not being there.  To me, she has always been the one with the most faith in and the most connection to Aslan.  For her not to there would have also gone against what Lewis already established about her as a character,   She is too generous and caring not to have been the one to go with him.