My 4 year old wants to read the same picture story book again and again, how do I vary it ??

I think if I'm on the same page (pun intended ^^) with you, I'll keep the book away from my child for some times and introduce a book that is of similar type to her. Like similar cover, perhaps characters but with different story? So as to get rid of the obsession a bit. But I know for sure it's like a "Eureka!" feeling again when they reunite. LOL Quoting from this article though explains why our kids love repetition over small things like your scenario: "To your toddler, so much of what she does is a new skill, and repetition is her way of remembering how to perform it the next time." http://www.parents.com/toddlers-preschoolers/development/behavioral/why-toddlers-love-repetition/