Yes, there are clearly THREE. One for the size 12s, one for the waistband of the longjohns, and the third would have to be from either the original size 6 panties or the shirt, or if the shirt was pushed up in the back, it could be from the folds of the white blanket underneath. What is clear to me is that the marks do not seem to go all the way around her (circumferential), unlike the ligature furrow. And their color (white) indicated postmortem pressure during UNfixed lividity. (closer to the TOD rather than later). Because no one saw the body in situ except JR and FW, we do not know the exact position of the blanket around her. We know the exact position of the BODY because she was in full rigor when found and brought up, remaining that way until the autopsy on the 27th, at which time rigor was beginning to dissipate or was "broken" by the coroner.
Keep in mind that although the waistbands of her clothing DO go all the way around her, death relaxes then hardens the flesh, and pressure on JB's corpse lying supine (on her back) is not equally distributed. The weight and gravity presses to the floor, or lowest point the body touches. Had JB been lying prone (on her stomach) the marks would be on her stomach and not her back. A LIVE person would not show such marks, even sleeping wearing the same clothing. For one, the flesh is soft and yielding in life, and also the garments would have to be fairly tight to make any mark, which would be red in a live person. Similar to a blouse with elastic at the wrist or pants with a snug elastic waist.