But instead I found an easier way...tablecloths!
I was at Target and they had a bunch of nice fabric tablecloths on clearance that were 60" x 120" which should work for my window. The prices were about $9 per tablecloth. This is definitely a better price than the home decor fabrics I was oggling at Joann's this past weekend ($15+/yard...ouch! And that was on sale. I would need about 16 yards!).
Since these tableclothes are long enough and all the edges are already finished, I only needed to make the top casing for the rod and to hem up the bottom. I hemmed the curtains with a few inches of overlap to the floor (to allow for shrinkage that will happen from multiple washings and someone told me that the sun can also shrink them, too). I didn't have to use scissors once. I decided to keep all the length and hem it up...just in case I need to let down a few inches later.
Making the curtains was a lot easier using the tablecloths because of all edges being finished, however, when I was pinning up the top and bottom edges, I noticed that the tablecloths didn't exactly have straight edges. So, that made it harder. But I'm satisfied with the finished product.