i increase the size by continuing to crochet the lattice part beyond the 6 rows it called for. I think I did 10 repeats instead of 6. The st count increases in the first row where the “bars” are. Finish the bar section, and go back to the lattice section, adding 10 rows again instead of 6. Don’t worry about the rippled or wavy edge. As it grows, the edges flatten out.