I’m of the opinion Marilyn was the caller Chris received at the pool and also at the house after Lyn’s disappearance whilst Joanne was within hearing distance
her strange jealousy in regard to Lynn having 20 blouses... how she must have longed for the moment when she could strut on in to Lynn's wardrobe and pick and choose, knowing Lynn wasn't coming back!
She doesn't mention that Lynn did a lot of sewing.. I recall that Chris wanted her to sew the girls dresses, and he wanted Joanne to sew their dresses too....