I am in need of pinwheel block beginning size. I love making pinwheels by Jenny's easy pinwheel way. She starts off with two 5" squares and sews all the way around the square, then cuts diagonal each direction. When she sews them together in the pinwheel, she said the finished block measures about 5 1/2 or 6 inches (I think). I am in need of a finished 24 1/2-25 inch block. What size of squares do you think I should begin with. Am I over thinking this and should I start with a 25 inch block and cut down to size? I'm designing my first quilt back instead of just seaming the fabric together. Thank you for all of your help.