why is susan not a friend to narnia
Susan Pevensie In The Last Battle, Susan is conspicuous by her absence. Peter says that she is "no longer a friend of Narnia", and (in Jill Pole's words) "she's interested in nothing now-a-days except nylons and lipstick and invitations." Similarly, Eustace Scrubb quotes her as saying, "What wonderful memories you have! Fancy you still thinking about all those funny games we used to play when we were children," and Polly Plummer adds, "She wasted all her school time wanting to be the age she is now, and she'll waste all the rest of her life trying to stay that age. Her whole idea is to race on to the silliest time of one's life as quick as she can and then stop there as long as she can." Thus, Susan does not enter the real Narnia with the others at the end of the series. It is left ambiguous whether Susan's absence is permanent, especially since Lewis stated elsewhere that:
The Chronicles of Narnia Set in the fictional realm of Narnia, a fantasy world of magic, mythical beasts, and talking animals, the series narrates the adventures of various children who play central roles in the unfolding history of that world. Except in The Horse and His Boy, the protagonists are all children from the real world, magically transported to Narnia, where they are called upon by the lion Aslan to protect Narnia from evil and restore the throne to its rightful line. The books span the entire history of Narnia, from its creation in The Magician's Nephew to its eventual destruction in The Last Battle.