Luckily I guessed right on this pajama set by ordering Small.  Normally I take size 8-10 US to allow for my sideways expansion, but at 5'2", if I order Medium it's usually too long.  In this case I find the width and the elastic waist fit are perfect for US Medium.  The sleeves and legs are about three inches too long, but the light fleece fabric is such that when you roll it up it clings to itself and stays up.  While the pants have no pockets, the top is long enough that you could pin it up to improvise a 5" pocket all the way around.  The weight of the fleece is just right to take the chill off indoors without being too hot or bulky like my onesie fleece hoodies. The set came with a slight "diesel" odor but it washed right out; the garment did not shrink, and even more to my surprise, the dark blue did not bleed at all into the color catcher I put in the washer.  I ordered two to start, and thanks to the great price and quality I've ordered a third one as well.