So... she's forgetful, and you want to give her something that makes people forgetful, perhaps..... She will become so forgetful, she forgets that she forgot and now she remembers! Brilliant!
Honestly, good luck with it. I hope you can bring them around. I've been quite the convert myself on the whole cannabis thing these past two years. I was never against it, but I wasn't exactly for it either. Seeing is believing. And I do think that a mix of Western and traditional medicine is the path.