Donna, for sure you could make this work. I have the sweater in small -- I am 5'4". Short waisted but long rise so overall an average torso length. I think medium would be plenty big for you.
Aida, I know -- it's a shame about the vest, eh? But I'm taking good care of it. One good thing -- it does "repair" pretty easily. (You know when you can draw the thread back into the fabric pretty well?)