Fellow authors will agree that a good beta reader is nearly impossible to come by. Those of Sarah’s caliber are gems that one finds unexpectedly and must respect for their rarity.
Sarah is probably one of the best I’ve ever used in terms of both her professionalism and thoroughness. Knowing her reactions as she worked through my manuscript gave me invaluable insight into my piece and, I believe, has improved it beyond measure. She works by chapter leaving both comments on google docs so that the author might see them ingrained with the piece, as well as a written review of her thoughts, the problems she has encountered and the things she enjoyed.
If you are lucky enough to deal with this beta reader be aware that you will not likely find another that is so committed to helping you. I highly recommend her services to those aiming to honestly improve their work.