SPOILER ALERT!
The Giving Tree - Shel Silverstein

The tree loves the boy and will do anything (and GIVE anything) to make him happy. But what happens when there is nothing left to give? After giving all she has, the only thing the tree has to offer is her stump to use as a seat. In the end, both the tree and the boy are content with being in each others presence.  I would use this book to talk about sharing with friends and loved ones! 

Lexile: 530L