Per the request of one of my lovely followers, I thought I'd offer a little tutorial of sewing a cornered piece of fabric. Oh, the pivoted corner against a gathered stitch, NEVER an easy part to sew. One of the repors I offer has a cornered yoke at the bust and I know that can be difficult.
Here is what I suggest:
This technique relies on paying attention to your seam allowance (SA). It will do a world of good for you to mark your SA ahead of time.
Baste the gathered side before you sew it to the other piece so the gathers don't shift on you. I know, another sewing step? yeah. Trust me, doing these little things helps tremendously when you sew, and after awhile it won't take more time. I put my basting stitches in the center of my SA, that way I don't have to worry about them showing or have a real need to take them out when I do my construction stitch.
The easiest way to do a baste is to adjust your machine to it's longest stitch setting, then just sew and back stitch at the end of the stitch in order to knot the thread.
Press the gathers down so they don't move as much. Also straighten out your gathers so you don't get puckers on the baste line. Also make sure your baste line is as straight as it can be. This will allow you to rest easy in knowing that your fabric is still straight.
Lay the pieces together and mark the seam allowance at the corner, that way you know where your needle is supposed to stop. Lay that first stitch as you would and sew and stop at the mark.
Now, depending on which piece of the fabric is pulling the most in the SA, you are going to want to notch at that corner with your scissors. Be careful not to take out all your SA, but take enough to relieve the stress of that corner. Shift your fabric behind the stitch, line your seam back up against the foot plate on the machine and continue your sewing.
Above is the start of that pivot where you can see it meets up to the SA mark of the white piece.
Simply press out the area and clean up the corner a bit.
Hope this helps. Have a great Saturday everyone.