Yes, Jennie Girl there is such a thing as a scant 1/4 inch. I've used in for years by appoximating with my eye, now, I don't need to figure it out anymore.
I recently purchased a Kenmore Machine that has many settings. One is the width of seams. There is a scant 1/4 inch, a 1/4 inch and a 3/4 inch seam width. I just turn a button and have the stitch I want.