Lucy wasn't in the Silver Chair! You probably mean [EDIT: Voyage of the Dawn Treader, rather], which was definitely my favorite for that reason. Lucy was a more interesting character than Peter. Silver Chair did have a great female character. CS Lewis knew how to write children in cool ways.
You're right. It was Jill and Eustace that went off to Narnia - but Eustace seemed kind of useless and Jill saved the day. (Maybe, it's been a while.) Peter wasn't in The Voyage of the Dawn Trader. It was Lucy's brother Edmund, no? Edmund who screwed things up badly in the Lion, the W and the W. -- and it was Lucy who found Narnia in the first place. Lucy: you go girl! As a kid, I spent a lot of time thinking about the world between worlds where some of the action of The Magician's Nephew took place. And now here we are in Hubski, a world between worlds.... or maybe Google is the world between worlds, where you can jump into any lake and emerge in a new world....