But here are some alternatives for the pre tied headscarf sewing pattern.
This one is free, they use quilting cotton. I would not use the padding, I think it would make the scarf super hot and sweaty. http://carolkimball.net/womens-chemo-scarf/
This is a pages with Jewish modest head coverings sewing patterns that will also work for chemo patients. They follow Shabbat and are closed on weekends and Jewish holidays.
Here is an alternative way to make any triangle scarf into a pretied with the help of a simple buckle.