If I'm seeing it right, I would simply go with the straight sewing all around it, then it would look as if it was what you intended in the first place.
And I had to go back to see what you meant by "crooked". Even then, I almost had to get a measuring tape to see it. Don't obsess about it, I've never, ever seen anyone gifted with a lovely thing like this whip out a tape and measure it. And later, no one would think of it. We usually have a kid or pet in our laps on top of it, no one cares much (except you) about such a small defect, if that is what it is.
I didn't see the first picture, if there was one, but even with a full sized quilt, the owner will be thrilled with it and not notice such a small thing.