That is really pretty! Based on what I've seen for embroidery designs, I doubt that is a set. I've been collecting designs of the correct size so I can put together a Valentine quilt similar to that one.
It's really rare that I find a set of embroidery patterns sold for making a quilt. I've seen sets for quilting motifs though. These blocks don't seem to have any unifying design element, and most collections do.
I'd suggest looking at some of the Embroidery Design websites, and picking out 12 blocks you like (make sure to get the size you want) and then selecting a set of colors and using them on all the blocks so in the end they do look like a set.