organiccbd, I have only made RSO twice, so I would defer to GrowGodess and NurseNancy on this one. They will be the ones to look to for info.
A couples points mentioned above that I agree with. I wouldn't focus on just cbd. Especially for what you're looking to treat. While cbd is a useful compound, it seems that there is a synergy, or "entourage effect" where canabinoids, terpenes, and other compounds work in unison to create the medicinal effects. Your oil should contain mostly high THC bud (from what I've read on the topic), and a much smaller percentage of cbd flowers. I treat a patient with an auto-immune disease, and one with seizures (dravets) and the high cbd oil is effective for both of them, but I am getting even better results with equal parts thc flowers added to the mix.
Also mentioned above, you could make a non-activated oil if your patient doesn't want to (or can't) get high. The RSO will absolutely lay your patient out. Especially until a tolerance is built. If this were my patient I might consider making both an activated RSO, and a non activated oil that won't get her high .... or at least not nearly as high. Perhaps she could take the RSO dose in the evening, allowing enough time before bed to go through the intensely uncomfortable high which if timed right would dissipate in time for adequate sleep. Then in the AM take a dose of the non-activated oil so that she can function during the day. I want to caution you on the non-activated oil though. I've really never heard of a cancer patient using this type of oil, so I can't ensure any therapeutic benefit to a cancer patient ..... at least to the degree that RSO seems to have. I think it might be a good combination though.
Here are a couple links that are posted elsewhere on RIU that might be of some use to you. Best of luck!
http://steephilllab.com/terpenes-and-cannabis/