Fridge Horror
Beth's beloved doll collection from Part I, and in particular her favorite doll Joanna, is never mentioned in Part II. The last mention of Joanna is when Amy paints a picture of her as a Christmas present for Beth after the latter recovers from her scarlet fever. Since Beth held Joanna in bed while she was sick, it seems likely that Joanna would have been burned, as was often done to belongings that scarlet fever patients had touched during their illness. (See, for example, The Velveteen Rabbit.) If this was indeed Joanna's fate, then imagine how hard it must have been for Beth, who still treated her dolls as if they were alive! Maybe Amy's painting of Joanna was for Beth to remember her by.
