As always, your writing is excellent. Thanks for continuing the story. That said, I have to admit to a bit of confusion.
First, I'm confused about Jack's height and the role it plays in the situation he's placed in at the neighbor's house. In response to one of my earlier comments you said, "I've been playing fast and loose with Jack's size this entire time! I can assure you, however, that it will all be explained in time and just adds further impetus for Jack to cooperate and behave." Then, in this most recent chapter, Jack describes Kyle as, "...despite being the same age as him, was taller even than Jessie. He stood at least a head and a half taller than Jack and Jack felt his nerve shrink as he realized he was afraid of the bigger boy." Yet, much earlier in the story Jessie was described as being only "a tiny bit taller than him [Jack]..." Given general statistics, the average male 12 y.o. is 61.5" (156.2 cm) and a "head and a half" would equate to about 12" - 15" meaning Jack is about 49" or less. But since Jessie is only a tiny bit taller than Jack why would Kyle not believe that Jack and Jessie are the same age. If I'm on track about Jack's height then it could be logical that he would be paired with Caitlyn, especially if she's big for her age and especially given Jack's punishment as a baby girl when they last met.
Second, could you be dropping hints that Kyle is treated younger than his age at times either as a punishment or just to keep him in line (e.g., "I still wipe Kyle’s face too, so no need to be so embarrassed”)? Certainly, if that's true, Kyle would not want to be associated with Jack and attract a similar punishment so age is just a ruse to distance himself from Jack.
Third, why is Diane so willing to let the neighbors think of Jack as much younger than Jessie and his true age and enforcing a feminine view of him, calling him a "tattletale princess" when he is dressed as a normal near-teen and we have no indication of him exhibiting any bad behavior. I think earlier comments that Diane can't be trusted are coming true.
Finally, why is Michael so accepting of Diane's treatment of Jack?
As I've said before, sorry to run on but I love this story and it's the realism and your excellent storytelling that keep me coming back for more.