Help with English crochet pattern

Hi, I'm having trouble with an English crochet pattern. I understand row 12, but I'm having trouble understanding rows 13 and 14. Thanks a lot, everyone! 

12. [7 sc, inc] three times, 21 sc  (48)13.  15 sc, ch 7, [sc] across the chs, sc in next st, 14 sc, [sc, dec] six times  (48)

14.  15 sc, sc up the opposite side of the chs, 33 sc  (54)  

Hi Christin,
I’ll give it a try. If you bought the pattern here on CP, though, it would probably be most helpful to message the designer directly :)

So after round 12 you have 48 sc, then in round 13 you crochet as follows:

15 sc = 15 single crochet stitches
ch 7 = 7 chain stitches
(sc) across the ch = crochet single crochet stitches back along the foundation chain = 6 single crochet stitches (because one of them is counted as a turning chain)
sc in next st = single crochet in the next single crochet stitch (probably at the base of the foundation chain, so one stitch next to the one where you started the chain stitches = 1 sc 
14 sc = 14 single crochet stitches
(sc, dec) six times = 6 * (single crochet, decrease) in a row = 12 sc
-> so after round 13 that’s a total of 15+6+1+14+12 = 48 sc

Round 14
15 sc = 15 single crochet stitches
sc up the opposite side of the chs = single crochet stitches along the back side of the foundation chain = 6 single crochet stitches 
33 sc = 33 sc (including the 6 sc back along the foundation chain again, although I don’t understand there either how you’re supposed to get around the corner of the foundation chain)
-> so after round 14 that’s a total of 15+6+33 = 54 sc

So mathematically I think it should work out like this, but right now I really can’t imagine what kind of shape that’s supposed to make? Or am I completely on the wrong track here?
Maybe there are others who have another idea about it?
Best regards and good luck!
Sarah