It sounds like your daughter is not reading books that are of interest to her.  Search the internet for book lists and recommendations, your local library is also a great resource. Giving a child their own library card is very empowering! Try to set up goals for her, either a book a day or a week depending on her skill level.  Lots of libraries have Summer Reading programs that give recognition to kids for reaching different levels. Gold for reading X-amount of books ect.  Hope this helps.

One thing you can try: Many of the public libraries now offer e-books.  These are stories that you can check out and download onto your ipod or computer.  The kids really like it because they can listen to the stories and follow along with the book.  It makes the stories more exciting and come to life.  It also takes all the hard work out of the reading but provides the vocabulary and concepts for the children.  Another idea: You can pick an author, do some research and background work on the author and try to read all of the author's books.  Then make it a contest of which book was the best, second best, etc.
It is very common, especially in the summer months that children do not want to read.  Just make it a routine every day.  At my house, we have a read in bed routine.  I grab a book and my kids grab their books and we read in our beds just before we turn out the lights.  It makes us all sleepy and becomes  a habit -  Have fun reading!

I highly recommend you read The Read-Aloud Handbook by Jim Trelease. It sites the reasons our children are reluctant readers and what we can do about it. Just by reading to our children even when they are old enough to read for themselves we can create a love of books in them. I had gotten away from reading to my oldest children when they were reading for themselves. I was only reading to the newest member of our family. In doing some research looking for books that I should have my kids read I came across this wonderful book and I jumped right back into reading for all three of my kids 9, 7 and 2. It has been wonderful - my 9 year old was a reluctant reader but he loves to be read to. My reading to him again has sparked an interest in him for books again and now he is doing more reading on his own. I hope you can find the time to read this book, it will be well worth your effort. Good luck!

Reading Challenge
Award prizes for a certain amount of time spent reading. Maybe a favorite dessert after dinner for an hour of reading, or a special activity after three hours of reading. Many kids would read more if their reward was a little tv time.

Thanks everyone for your responses. I tried some new things and it is starting to work.

I have the same problem with my 7 year old. He was in the advanced reading class in 1st grade because he is an excellent reader, but yet he does not care to read. He would rather be doing other things. I have taken him to the library to let him pick out the Chapter books he would like to read but when he gets them home he doesn't read them. I have also checked out a few books on CD. He likes to listen to them but sometimes he doesn't have the patience just to sit there and listen. I will say that he does like to write in a journal from time to time though. Making up stories as they come to him. You may want to encourage your daughter to start  her very own summer journal. Just stop by the store and pick up any composition notebook or whatever she may like (something girlie, lol) to use to write in. A journal not only helps with reading and writing but also encourages critical thinking. Then maybe she can read parts of her journal to you. : )

What she likes is out there. You just have to help her find it. Beware literary pretension. Books about hobbies and personal interests. Magazines, magazines, magazines.

I had the same issue in getting my children to read for their 20 minutes a day as part of their homework assignment.Finally, I got them a library card and allowed them to pick 3  books each. At night, I made it as part of our routine before bedtime that we all lay together and i listen to them read plus help them pronounce words then i ask them about the story or ask them what do they think is happening in the story etc...then i pull out my own book and tell them to close their eyes and imagine the story in their heads....wow they fall asleep so fast...reading with your children is key, plus it creates a special bond =) also when they do well at school such as good gradesbehavior I reward them by letting them purchase one book at barnes and noble..they love that...and also the movie Inkheart inspired them to want to read even more...the more you surround their lives with reading the more they draw themselves to it and want it...try their favorite magazines also or cookbooks...goodluck