If you buy the Kindle book (usually $4.99–$5.99 USD), you can legally convert it to EPub using open-source software like (provided you remove DRM for personal use only). This is technically a grey area but is widely accepted for personal backup.
Check your local library. Many library systems purchase Elsie Silver’s books. Using the , you can borrow the book and send an EPub version directly to your Kobo or other EPub-compatible device. Note: Availability depends on your region. Hopeless By Elsie Silver EPub Download