I bought mine at best shop I have ever been to since I started vaping https://vapingdaily.com/

My stepmother had lung cancer too. We tried a lot of things you know. It was actually a combination of surgery, chemotherapy, targeted therapy, immunotherapy.
While treatment she used dry herb vaporizer. SO maybe your mom will apreciate it too. For those who don't know - dry herb tanks are a type of a vape tank, that is typically attached to box mod or a vape pen using 510-connection, that allows you to vape dry herbs, without purchasing a separate vaporizer for that. At Vaping Daily there are many types. I hope this will help https://vapingdaily.com/dry-herb-atomizer-tanks/