Make sure if you have any ideas to write them down, and give them to her. If you have seen something sketch it out, or bring the pattern that may show quilting ideas.
Most of us have our own thread, batting on a roll can be a better cost for you, and I believe they are nicer that single batts that are rolled into a small package.
Designs~ask them if they have ideas and be open to listen... she may have done one similar.
Build a relationship with your longarmer... I know I feel my quilt makers are my friends.
Enjoy your quilt! I'm sure it will be wonderful when you get it back.