Completely normal. She is learning through all her senses, not just reading a book like adults do. :)
When my son was constantly chewing the corners off all of his books, we picked up one vinyl book and about 3 fabric books. He used those pretty exclusively for a couple months, in order for us to prevent further destruction to his board books. We only used the board books under close supervision or when my husband and I were reading to him. Eventually he figured out that he could have the special books (the non-vinyl and non-cloth ones) if he kept them out of his mouth and now at 31 months, he is responsible even with books with regular paper pages.
Give her time and keep reading to her...then give her safe books to use on her own. Encourage her to explore those safe books!