U-Shaped Stairwell

[JDODEZ]

I already installed the stairs. However, the stairs are facing (or open) to a two story family room. When you walk up to the landing you can see over into the family room. When I add the CURVED WALL it goes to the ceiling and does not give me the opening. I can not figure out how to shorten the wall from the ceiling. If I just add the stairs and landing, it doesn't want to make a good curve, it is more octagon. If I add the curve wall at the second floor it is too high. The landing is mid way between the two floors.
Any suggestions??