what types of things interest her? That can make a big difference in what books will appeal to her. I have 9.5YO twin daughters who both love to read, but their interests, and consequently their reading lists, are VERY different.
DD1 likes historical fiction and nonfiction books about her favorite animals (sea otters, pandas, etc.) and historical eras (mostly related to opera and classical music/composers). Some of her favorite series are the American Girl, Dear America, and Royal Diaries historical fiction. She also enjoys Beverly Cleary books (thought Henry Huggins was especially amusing)
DD2 likes fantasy fiction and mysteries. Her favorites include Erin Hunter's "Warriors" books (about a society of feral cats), Jenny Nimmo's "Charlie Bone" series, Georgia Byng's "Molly Moon" books, Rick Riordan's "Percy Jackson" books, the "39 Clues" books (various authors), Christopher Paolini's "Eragon" series... will post back when I think of more, she read a TON this past year.
Some books they both like include Grace Lin's "Where the Mountain Meets the Moon" (an adventure with roots in old Chinese folk tales), Trenton Lee Stewart's "Mysterious Benedict Society" (I think there are 3 books to that series so far), the historical fiction books by Yoshiko Uchida (Journey to Topaz, Journey Home, A Jar of Dreams, etc. - stories of Japanese-Americans in the '30s and '40s - DH's mom is Japanese-American and the stories are set in the era she grew up in),