Here Myra holds the finished product. The frame that holds the bed is quite well constructed, but the bottom of the bed, when it came from IKEA, was essentially thick cardboard. I think it lasted less than 1 day before Logan broke it by standing on it.
So I cut a section of the same 1/2 inch plywood as a new bottom. Glue up below:
It seems that the bed meets with baby doll approval.