If the evening began with Patsy legitimately getting her ready for bed- it was winter. Kids kick off bedcovers. Asleep or not, I'd have still put some type of pajama bottom or longjohns on her, so Patsy saying she put the longjohns on really isn't unusual to me.
We don't know if Patsy is lying through her teeth. How could we? JB may very well have worn the pink pajama bottoms instead of the longjohns when she got home from the White's, and left the white shirt on. This theory fits as well, especially since the pink bottoms seem to be unaccounted for (as well as any size 6 panties she may have worn that day.
There WAS a pair soiled with fecal matter lying on JB's floor (not sure if it was the bathroom floor or her room- I have read both) inside a pair of black pants. Patsy was questioned about this, and said it wasn't the black pants she wore to the White's (which were velvet) but instead was a pair of black "play pants" she wore earlier in the day. I have always been suspicious about that. While plenty of little girls have black cotton or corduroy play pants, I believe these pants seen on the floor with the fecal stains in them were, in fact, the black velvet pants she wore to the White's. Her soiling them was probably the kicking off point for Patsy that evening. She was tired, stressed from the busy Christmas, and still had to get things in order for a trip she really didn't want to make. She was to meet her stepdaughter's new fiance for the first time. She then was going on to yet another family holiday on a Disney Cruise, where she would "celebrate" turning 40. BIG time stress stuff. JB soiling herself yet again was something she really didn't deal with too well.
We don't know what became of the pink pajama bottoms, OR the black velvet pants she wore to the White's that day. LE didn't really ask about them, as far as I know.
Letting a child have a bedtime snack wearing pajamas is something any parent would do. JB wet the bed every night anyway. Patsy had the sheets changed every day anyway. Cranky kids who may not have eaten much at a party, the excitement of Christmas, the presents, etc. Kids who are hungry at bedtime do not fall asleep. A snack would not seem unusual.
I also believe she never went to bed that night.
Obviously when she was assaulted, she was naked from the waist down. She bled onto her thighs and pubic area, and there was no blood on her longjohns. If she was wearing the pink bottoms, possibly they were bloodied, along with her original panties. The lonhjogns and size 12 panties were added to replace them.
We also can't assume that Patsy had to go back upstairs to get the longjohns (if they were not originally put on her)- they may have been in the basement dryer along with the white blanket. We really don't know the truth here about the pink bottoms, longjohns and black velvet pants. We can assume it was JR who redressed her because of his wool shirt fibers being found in the new panties.
Obviously the whole point of saying this wasn't a pedophile is that, just as you say, a pedophile wouldn't have redressed her anyway. I suppose they COULD have left her naked from the waist down and wrapped in her blanket, but - and this is one more thing that points to the parents' involvement- I can't see Patsy wanting JB found that way. It was all about how she would be found. They wanted to mask the sexual assault, at least to outward appearances. That is why, IMO, they both got so defensive when confronted with the evidence of sexual abuse. Patsy demanding to know "show me where it says that" and JR saying they were trying to disgrace his "relationship with his daughter".
JB could just as easily have been redressed in the longjohns whether or not she was originally wearing them. There is nothing that suggests she was or was not wearing them when she got home. Could have been either.
Frankly, she could also have been wearing the pink nightie, then been redressed in the white top and longjohns. There was a small amount of blood on the pink nightie, which could have happened at the time of the assault or could have happened as she was being cleaned up.
Again, we really have no way to know for sure WHAT she wore originally to bed.
I feel the pineapple snack was eaten in whatever Patsy dressed her in for bed. It could be any of the mentioned garments: the pink Barbie nightie, the white top and longjohns, the white top and missing pink bottoms, the pink pajama top and bottom, and throw the red turtleneck in there too somewhere. Several possibilities. Was the red turtleneck ever tested for blood/urine? I don't think so. I don't think Patsy needed to put a "condition" on JB wearing anything specific in order to have a bedtime snack. She may have said "OK, you can have a snack after you get ready for bed". Or JB may have had the snack while still dressed in her outfit she wore to the White's. Then, if she soiled her pants after eating the pineapple, I can totally see Patsy exploding over that.
There are so many variables in this case. People, clothing, actions. Lies surrounding all of it, NO witnesses that were not family members (that we are aware of). An inadequate and weak DA, incompetent police. Shady relationships with the defense. Put it all together and no wonder we are here all these years later still talking about what she was wearing when she died, what room she died in, and the exact TOD. Things that should have been determined in the first weeks of the investigation, or at least before the house was turned back over to the family and especially before ANYONE who was NOT LE was allowed back inside to remove stuff. Frankly after Aunt P went over there, the investigation was pretty much over at that point.