Marijuana for me during chemotherapy was godsend.

All the medicines I was taking for chemotherapy, I stopped taking for the last 2 cycles, because weed literally help suppress all the symptoms. I even did light work-outs because weed helped that much.

However, if the smell irritates her, she can't smoke it. Everything that smells not so good to a person intensifies with chemo, making her feel sickly. If she were to take it, it'd have to be through food.

But respect her wishes none the less. Most important thing is to support her and love her, show her strength and optimism.