The Friends We Keep
by Holly Chamberlin
The Friends We Keep is about three friends (Sophie, Eva, & John) who lost touch, and reunite again twenty years later. It's the story of them rediscovering themselves and each other, including betrayals and hookups.
I think Eva was the most realistic and developed character and the one that I found myself rooting for throughout the book.
I'd say this is a good beach read if you give it a chance to get going.