Is your friend who's doing the around the world by hand starting at the center or along an edge? And what size are her squares?
If you do it by hand, I think it's really easier to start at the center and just add one color at a time in stairsteps around using one continuous thread. I'm to the last few rounds at the corners on mine. Definitely a lengthy project (2.5" squares, queen/king size), but well worth it, as I'm considering this one my triumph of color coordination...a collection of greens that "shouldn't" have looked right together but are coming out gorgeous (if I may say so myself!)
Tell her to hang in there...it really is worth all the time and effort. When the sides of the diamond get really big (more than ten squares per side) it helps to set a goal of just getting one side done today or this week, rather than "oh my goodness, how can I get 4x19 done in this lifetime...and I'll still have to work my way out to the corners...it's not even halfway done..." Ask me how I know??? Mine almost became a card table cover at one point!