Q: This was my aunt’s book, Treasure Island, and there is no copyright date on the inside page. She was born in 1908. I would appreciate any information you can give me.

A: Your book was published in 1915 as part of the Vademecum Series.
It originally was sold in a labeled box. See below. 
See: http://www.henryaltemus.com/series/series180.htm
It a a reprint with nominal value.