Dawn: go to message # 112 in this thread and you'll see an example of adding the 1/4" to the pattern.
I think the wording is funky about the 1/4" (don't have my book with me right now) but you have to have the 1/4" on them for them to work out to be 12". I think she is making sure it's 1/4" from the outside line that she has drawn in the book...not to cut off the 1/4" inch.
Good luck and I'm sure someone else can help you too.
Love the red on the star...it really pops out.