A healthy body is most important for any child or adult. Discuss all issues related to health in this forum.
Have you tried to replace the bedsheets, pillows, and stuff into those made from organic materials? My little sister had the same sleeping problems, and when we chanced all that stuff, the situation got better. All my family changed our bedsheets and blanket covers after that accident into cotton ones, and the quality and length of sleeping incresed. I bought mine over here https://www.melacomfort.co.uk/products/ ... nket-cover and can say that it was a lifesaver for me. I don't know if it'll help you, but give it a try.
The type of mattress she uses also makes a difference. My friend had a lot of sleep issues due to her back pain and so she researched a lot (https://bestkitchenbuy.com/coir-mattres ... back-pain/) and found the right mattress that she felt most comfortable in. There are such guides that really help us in boosting up