SOLVED. Middle Grade. Two Siblings Sail in Fantasy Adventure Portal book. Read around 2006-2007. [s]

[Madison]

I read a large chapter book while in 5th grade, around the year 2006-07. It was a THICK book probably meant for middle school age, so still child not YA.
Description:
Two siblings, a brother and sister, find or are gifted a magic book that takes them on an adventure. They run into many different obstacles in trying to find their way back home, one of which I remember a beautiful, colorful island being described. I remember the older brother wanted to not go on the adventures, and the little sister insisted. The cover, at the time, showed a stormy ocean with a small row boat, an older brother and little sister. The brother’s face was “looking at you” in worry. It was outlined in a maroon trim on the cover that made me feel the book was “old” as a child. Please help! It’s eating me alive I can’t find this one favorite childhood novel!

[Capn]

When you say 'maroon trim', do you mean the border on the cover of an old apple Scholastic paperback (examples here: https://www.goodreads.com/list/show/8...) or Avon Camelot (https://www.goodreads.com/list/show/1...), that sort of thing? :)

How 'thick' are we talking - a brick of a book of 500 pages, or more like the 200 - 350 range?

There's a specific list for this kind of story, anyway: Book Jumping or Book Travelling -
https://www.goodreads.com/list/show/1...
or here: https://www.goodreads.com/list/show/1... - anything on these two lists looking familiar? :)

[Orsolya Könyvtáros (formerly Memp)]

Your description of the cover reminds me of The Book of Story Beginnings by Kristin Kladstrup. The little girl isn't in the boat but there is an oval portrait of her on the (maroon) spine of the book.

[Madison]

Thank you @Memp! Solved! :) You’re awesome!