The stitching is neat and the edge is a sewn knife edge. The filling seems to be natural, a thin cotton wadding. The quilt comes from the Whitley Bay area of Northumberland.
The fabric is a man-made one - these were well liked for their hard wearing qualities. The first totally artifical fibre, Nylon, was developed in 1938 but did not appear on the market until after WWII. Rayon, or artifical silk, was popular from the 1930s to the 1950's and was made of cellulose, the natural compound. Acetate is a version of rayon.
I imagine that this quilt dates from the 40s or 50s but it would be nice to identify the fibre more precisely.