To make the size bed you want, I am pretty sure you will probably need more fabric if you don't want a lot of the white you have.. 1 jelly roll is about 2.78 yards before any seams. Each 40 piece charm pack is about 25 inches, you have four so that is 100 inches or another 2.78 yards. so you only have about 5.6 yards of fabric, minus what you have to use up in the seams. Do you have another color in yardage that would go with what you have? That maybe could be used for sashing or a border?