To get to size:
v-st: (dc, ch 1, dc) in same st
Rnd 8: White, {(v-st, ch 2, v-st) in corner, sk 2 st, (v-st in next, sk 2 st) 6 times} 4 times.
Rnd 9: Baby blue, {5 sc in corner, (sk 1st dc of next v-st, sc in ch-1 sp, sk 2nd dc of v-st, sc bet v-st containing the ch-1 sp just worked and the next v-st) 6 times, rep bet * and * once} 4 times.
Rnd 10: 5 sc corners, sc around increasing by 2 sts on each side (21 + corner st)