Originally Posted by ohmisslizzie
So I can make it all the way across following the same measurments she gives for cutting pieces and it will come out right?
That pattern has you cut strips across the width of the fabric, which makes each strip about 42" long. That is not long enough to go across the bed. That is why the original pattern has you sew these strips together to make 2 panels that are 42" wide, then sew the panels together down the middle to make a top about 84" wide. It is that seam down the middle that makes it look like two twin quilts sewn together.
My suggestion was to make the two panels as described in the pattern, then cut one of them in half. Put the wide panel in the middle, and use the two halves as side panels. The cutting measurements for that pattern will work if you do it this way. You will lose just a little in the width by making two seams instead of one, but that shouldn't matter in the finished quilt.
If you want continuous strips going across the quilt, you need to cut your strips on the lengthwise grain of the fabric. In that case, ideally you want each piece of fabric to be at least 2-1/3 yards long (so each strip is about 84" long instead of 42" long).
I should add that if this is your first quilt, you may not be able to finish it by Christmas; it may take you longer to make than you expect, especially if you have to learn each step as you go.