BBM The accounts written about John and Burke assembling a toy together place them on the main floor - living room, near the Christmas tree, IIRC. Your observation that we are supposed to consider John and Burke being together for a period of time, away from Patsy while she is alone with JB, does lead to interesting thought. Then, Patsy is supposed to have gone about more packing chores, while John and Burke continue to ready Burke for bed (without Patsy knowing for sure), yet Patsy is then said to be in bed ahead of JR arriving there for some quick reading after taking his melatonin.
If Patsy was busy gathering clothing from JB's and Burke's room, or even the laundry area there on the children's floor, then taking things to JAR's room to put with things for the Disney trip, at the same time JR and Burke would have come up to put Burke to bed, how did they avoid running into each other on that floor? Wouldn't Patsy have had to complete her packing chores and made it to bed before Burke and JR came up and went through the bedtime thing?
If we are to believe the R's, then JB was carried to bed, Patsy got her tucked in, worked on the Disney trip for a bit while JR and Burke were working on the toy in the living room, but Patsy went off to bed prior to JR and Burke coming up, and JR then going to his room where Patsy was already in bed. The last person up and around then, according to their own reports, would have been JR. Not saying that the kids could not have then gotten up and everything turned upside down - but I cannot help but think JR would have peeked in on JB before retiring.