Ahhh sisters. I don't have any (at least not biologically) but as far as I am concerned my godsisters, sister-in-laws, friends and close female cousins are my sisters :).
I have recently created some too cute pages that are perfect for celebrating that sisterly love. (They are all available to buy now on my eBay page).
Came across this cute book that combines pictures of animals with quotes about sister :)