Sorry for my delay in responding to your question regarding the Twinkle Twinkle Little Star pattern, i was away from the office for a few weeks.
At the end of Row 13 you are going to knit the last edging st together with the shawl st. This will be continued for rows 15, 17, 19 and then on row 21 you slip the last 2 sts of the edging to right-hand needle, knit the st on the shawl, pass over the slipped sts.
For rows 3, 5, 7, and 9 you repeat the same as row 13 for joining the edging. Row 1 - knit the last 2 sts of the edging together with the 1st on the shawl; knit 3 sts together. Row 9 - Knit the last edging st together with shawl st, and knit 1 st into next st on shawl - 14 sts.
If you have any further questions, you can email me directly at firstname.lastname@example.org.
All my best,