How to shorten and recover a readymade Roman shade

After my huge success recovering a cheap blackout Roman shade for Lucy's room with some pretty block print fabric, I decided I need at least one more custom fabric shade! Our upstairs bathroom gets crazy sun in the afternoons and I knew I'd have to hang something pretty but also very functional there. (We renovated it last fall, and it's not a problem in the fall/winter.) The problem with my readymade blackout shade project? The cheap Roman shades only come in a couple lengths (like 60") and tha...