Hello Scallywag,

Welcome to Neurotalk Support Groups.

I am so sorry to hear about your friend. Those are a lot of big changes to go through. There are many supportive people here so hopefully you will find some information that is helpful for her.

You might find some suggestions here...
Traumatic Brain Injury and Post Concussion Syndrome

I can't answer to the cannabis questions but I can recommend a great video from TEDtalks by Jane Macgonigal who suffered from PCS herself and developed the game "Superbetter". The talk is about her journey back from a place where every stimulus was causing pain and problems.
https://www.ted.com/talks/jane_mcgon..._years_of_life

I hope your friend finds relief and healing soon. You are a dear to be there for her.