Building stair railing/half wall

[mrw]

Hello

I have a "U" staircase that used to have a banister from floor to ceiling around it.
Now, I want to build a half-wall around the staircase instead, but due to the placement of the front door, I only have room for a 45 stud + OSB and plasterboard.
I was thinking of letting the OSB extend down into the stairwell a bit and screw into the edge of the joist.

Will that work or is there a risk that the wall will become wobbly?

The red-marked area in the non-scale accurate image is the prospective wall

 

[Amiz81]

Facing the same problem, did you come up with a good solution?

 

[mrw]

Hi
Bolted a 45x45 stud to the floor with French wood screws and built on it.
It became incredibly stable, and so far, I've only put drywall on one side, no OSB at all.
-/cw

 

[MVJK]

Do you have a picture of how it turned out? I'm working on a similar build but chose steel studs - maybe a mistake. It's difficult to get it completely stable on all parts of the half-wall.