Now I checked some parts of season 2 and finally found very good bedroom scenes.
First pic showing the boys room. John-Boy, Jim-Bob and Jason (from left). John-Boy has a room of his own (see main entry) so I think Ben sleeps there where John-Boy sits. Jason wearing as usual bib overalls.
The 2nd pic showing the girls room. Elizabeth, Erin and Mary-Ellen. Jim-Bob and Elizabeth sharing one room at season 1 (see separate entry/main entry). All pics I think from s2e2. Wooden beds for boys, metal beds for girls or are these painted wood beds? At least different beds.
I still have to check the complete series, especially the later seasons. But I doubt that there will be better pics showing all 3 beds. But I try to find some better, other perspectives as well.
Strange arrangement of the beds. Especially of the girls room. Maybe the room is smaller. Do they have to jump from bed to bed?