first, how did you walk away from that fabric at the LQS with only buying one yard?? LOL. It is beautiful. So are your fairy frosts. But IMHO, you need another color value to add in. Your two fairy frosts are definitely mediums to light in value. Your print would qualify as a light. You need more contrast so a dark would be in order. Otherwise, I fear your completed lap quilt may end up looking a bit washed out due to almost no contrast. I see at least two or three darks in your focus fabric you could pull from. The deep rose, the deep greenish gray in the rose leaves or one of the dark greys that are in the birds.
I agree with the posters who say use your focus as a panel in the center then build out around it round robin style. The design in your print that is just above the word "Rosa" I would try to find a block design that somewhat mimics that. Try Quilters Cache
http://www.quilterscache.com/QuiltBlocksGalore.html I am sure there would be something in there that would somewhat mimic that. I browsed for just a minute and found this one:
http://www.quilterscache.com/C/CainandAbelBlock.html
It makes a 10" block.
If this were mine, I would audition a very thin dark border around my focus fabric, like finish at 1/2" (so that would be a 1" cut of strips). Maybe up to 1" but no wider. I would add a solid white or a WOW fabric to the mix that matches the focus and make blocks that mimic that "tile", for lack of a better word, with the white and one, or both of the fairy frosts and maybe even a touch of the dark. I would do one row of those. Either all green, all lilac/rose or alternating between the two colors. I would have to audition to see which I liked better. I may put another dark narrow border, that you never know until you get laid out on a design wall. The next row I think a lilac and green checkerboard would be lovely but it may need more dark or more white so you may opt to do one of the fairy frosts and a dark or white to make the checkerboard. Again I would not make my finished squares much larger than 2" square. The size would be determined by how big your quilt is at this point and you would want a size that is evenly divisible. By this round you should have a fairly good size lap quilt. Use your leftover fairy frosts for a srappy binding.