John Colley's Answer:
OK, lets try to identify the problems here:
You are working in a dynamic and innovative area which demands flexibility and initiative on a pilot project which needs to get sales and promotion going. Your coworker does not exhibit these skills.
Your supervisor is not supervising or providing you with the authority to supervise
I think you need to take two separate actions simultaneously: deal with your supervisor and deal with your coworker. So in no particular order;
1. Your Supervisor
You need to enlist the authority of your Supervisor to empower you. I would suggest that you adopt a non-threatening approach along the lines of if this pilot project succeeds you, the supervisor, will get the credit from his boss.
Stress you are keen to take the initiative and, in the absence of the official supervisor who was laid off, you want him to give you temporary supervisory authority on this project to ensure it is a success.
Stress to him that failure on his part to do this may compromise the project due to lack of direction. An email trail to this effect will also stand you in good stead should he chose to frustrate you, although broadly speaking I am not in favour of purely "protectionist" emails.
If you get nowhere with your supervisor, the nuclear option is to go to his boss and table the issue.
2. Your Co-worker
If your co-worker needs lists and structure then I would recommend that you work with her to create them.
I suggest that you sit down with her and say, "We both know that this project has lots of detail and complexities to it and that neither one of us has all the answers. So we are going to work together to create the systems and structure as we go"
Remember, creativity can be chaotic but business needs structure.
It seems that your co-worker is uncomfortable without it and needs a set of rails to run on.
The first step is to brainstorm together and get all your ideas down on a sheet of paper and then organise them. Use a mind map to do this or create a document (eg in Google docs) that you can both access.
Ensure that she understands that she is free to add new steps as required. In addition keep a comments column to collect ideas and feedback from your work as it goes along. You will need a "completed by" column and a date, encouraging her to complete this as you go.
Agree to have a start of the day 10 minutes to prioritise the work for the day and agreed to have a two way flow of information. Have an end of day mutual debrief and progress check to discuss what has gone well and been completed. Also identify where progress has not been achieved and discuss why not and what you both have to do to rectify the situation. Make sure you have some examples of your own to table so that this does not feel like an interrogation.
I am recommending a "this is how WE have to get this done approach" but you will need her buy-in and acceptance to this process.
I strongly recommend you both read Atul Gawande's book The Checklist Manifesto for more ideas.
Make sure that you capture what you create and then present this structure and system to your supervisory as a blue print for future pilot projects, copied into the rest of the senior members of your company when you have finished.
It is clear that you have lots of self-motivation and ability. Turn this problem into an opportunity to show your senior colleagues what you are capable of and help them to better understand your value to the company. Who knows, there is already a supervisor vacancy...