A seamstress is not a patternmaker. If you are looking for someone to make patterns, do not ask a seamstress. A patternmaker can sew, but if I call myself a seamstress, I am not implying that I can make patterns. If a patternmaker says he/she can't sew then find yourself another patternmaker.
I was asked many years ago to sew samples for a self-described patternmaker who lamented that she could only draft patterns but could not sew to save her life. After contracting to sew 10 designs, already cut out, for $50.00 apiece I discovered the problem. Nothing fit together. She couldn't sew because she couldn't draft. I was inexperienced at the time and brought the garments to a experienced patternmaker. She confirmed my discovery. I gave it all back and didn't charge her anything because she had spent $5000.00 for a booth at a show.
If you don't know this basic truth, its time to stop. You aren't ready for production. Go here, buy her book.