The bookplate is within 1925's The Golden Porch: A Book of Greek Fairy Tales, written by W.M.L. Hutchinson and published by Cadmus Books. The name "Diane Rosales" is written in neat cursive on the bookplate, which is dated January 22, 1947.
The dragon and Pinocchio (helping Alice) are particularly cute aspects of the "storybook come to life" illustration.
If you're interested in doing bookplates for your own book collection, a great place to start might be the free downloads offered by British author Anne Fine at her My Home Library website. There are awesome bookplates in all shapes and sizes, featuring the work of professional artists and illustrators. It's an awesome resource that Fine has put together, and all you need is a color printer!
Meanwhile, here are two more cool things from inside The Golden Porch...
First up is the nifty logo for Cadmus Books.
And second is this Dugald Stewart Walker illustration of Medusa.
Coincidentally, Walker is remembered partly for the individualized bookplates that he designed on commission. Some of these can be viewed at the Library of Virginia's Virginia Memory website.