A simplified, untested pattern inspired by the photo—not an exact reproduction. US crochet terms.
Materials: Royal blue, light blue, and white cotton yarn; 3 mm hook; scissors; yarn needle.
Abbreviations: ch = chain, sl st = slip stitch, sc = single crochet, hdc = half double crochet, dc = double crochet, tr = treble crochet.
Puff stitch: Yarn over, insert hook into the indicated stitch, pull up a loop; repeat three times total. Yarn over and pull through all 7 loops, then ch 1 to close.
Round 1 — Royal blue
Make a magic ring. Ch 3 (counts as a dc), work 11 dc into the ring. Tighten and join. 12 dc.
Round 2 — Light blue
Work one puff into each dc, followed by an additional ch 1 between puffs. Join to the first puff. 12 puffs and 12 spaces.
Round 3 — White
Work 2 sc into each space between puffs. Join. 24 sc.
Round 4 — Royal blue
Ch 3 (counts as the first dc), dc in the same stitch, then 2 dc in each remaining stitch. Join. 48 dc.
Round 5 — Shape the six points
With light blue, repeat this sequence 6 times, working across 8 stitches each time:
Sl st in the next stitch, sc in the next, hdc in the next, dc in the next, (2 tr, ch 2, 2 tr) in the next, dc in the next, hdc in the next, sc in the next.
Join and fasten off.
Round 6 — Border
With white, sc around, working 3 sc into each ch-2 tip and a sl st into each valley. Join.
Hanging loop: At one tip, ch 30 and sl st back into the same stitch. Secure and weave in all ends.
Lightly dampen, pin the six points into shape, and let dry flat. Swap the three colors between rounds to create a matching set of four stars.