You could print out or draw up some layout sketches for her.
Also, keep in mind that you don't necessarily need to make/buy a bunch of Alaska or cruise specific embellishments for her. Think about the pictures she'll most likely be taking, and go from there.
Scenery pictures will mostly be blues, greys and greens. Give her papers, ribbons, etc that will coordinate with those. Pictures around the ship and of your parents at dinner will most likely be very colorful, so perhaps go will simple black and white papers and embellishments for those pages.
Also, paint covers a multitude of sins and can be much less expensive than buying tons of patterned paper.
I hope she has a great time on the cruise and loves your gift!