There is a railing around the opening where the stairs come up to the upper floor. 3 posts have solid support from the wall and each other, but the 4th one, located at the entrance, doesn't have much support. It goes down into the floor and is anchored in the floor joists, but that's not enough. It's wobbly from the start, and the more times the children pass, the looser it becomes. I think I've seen some angle bracket variant for these kinds of problems. The house is from the mid-1800s, so it should match that style. Does anyone have tips on something useful and where to get it?
A bit difficult to say without a picture, but if you want it in an older style, perhaps a piece of smide would be fitting.. That is, to create a nice bracket.