Blackbeard, I'm a leftie too. My solution to the problem is to the follow the directions in Barb's book but imagine myself looking in a mirror.
I've used this trick since I was in first grade as a way to deal with living in a right-handed world.
I simply cross my left leg over my right, tuck the Fell under my left knee and stitch with my left hand just the way Barb does but from the other side of the pleat edge.