I'm sorry to hear about your aunt. I wish her the best of luck with her treatment and recovery!
The thing that is important to realize about cancer is that, unlike many other diseases, it is very complex in the fact that it is actually not a single disease at all, but a collection of many different diseases which all lead to uncontrolled proliferation of cells. The resulting cancerous tissues eventually invade healthy organs and interrupt their normal function, leading to death.
One bit of advice I can give is that when you go searching for peer-reviewed medical evidence, make sure you thoroughly read and accurately interpret the studies you are looking at. Many people have the tendency to misinterpret scientific studies, especially when it comes to "in vitro" and "in vivo" results. Often times you see studies showing that a particular compound has particular effects "in vitro", which is Latin for "in glass" and means that the effects were observed in cultured cells in a test tube, not in a living organism of any kind. Successful in vitro results sometimes mean, but do not always mean successful in-vivo results (in vivo tests are those carried out in living organisms).
The claim that "nobody who smokes pot has ever died of cancer" is 100%, absolutely false, although cannabis use itself is not in any way associated with cancer.
The fact of the matter is, even if there is adequate evidence to suggest that a compound has therapeutic potential against cancer, as is the case with many Cannabinoids, there is no "silver bullet". To date, there is no substance that will magically "cure" any and all cancers, and due to the very nature of cancer as a disease, there likely never will be.
When it comes to Cannabis, the evidence suggesting that it has anti-proliferative (anti-cancerous) activity is very strong, but it should still only ever be used as part of a treatment regime and not as a standalone treatment.
Might I recommend that if you wish you help your aunt succeed in her recovery with more natural methods and don't think she would be accepting towards the idea of Cannabis, there are other options. Cannabis is just one of many plants that contain pharmacologically active substances. In fact, Taxanes, which are commonly prescribed as chemotherapy agents in the treatment of some types of cancer, are natural compounds extracted from the Yew tree. As a precautionary side note, do not attempt to use your own home-made yew concoctions. I'm not saying you would do this, as it's not like these products are widely available, but just so you are aware it is deadly if used incorrectly by someone who is not an extremely skilled medical professional.
One of the most effective, and safest "natural" treatments for cancer are a group of polysaccharides and beta-glucans found in medicinal mushrooms such as Reishi, Chaga, Turkey Tail, etc. More accurately, these compounds are immunostimulants that stimulate your bodies natural immune response against cancer cells. The University of Texas MD Anderson Cancer Center, which, if I am not mistaken, is recognized as the worlds most renowned cancer treatment facility, actually uses an adjuvant cancer therapy based on these naturally occurring polysaccharides alongside conventional chemotherapy to 1) help the immune system identify and kill cancer cells and 2) reduce the negative side effects of chemotherapy and radiation therapy.
I personally have been taking Chaga mushroom for the past 6 or 7 years. I harvest it wild as it grows wild around here and I live in a rural area with lots of forests, but it is widely available online. It's one of the only "herbal remedies" I would ever actually recommend to someone. I personally have a lot of experience with it, and people from all corners of the world have been consuming this stuff in one way, shape or form for over a millennium. Its one of the better researched "natural remedies" out there. Its also great because it has virtually no taste, despite it being a brown/black mushroom with a very frightening appearance.
Another option is high CBD hemp. Most of the studies suggesting that Cannabis has anti-proliferative activity actually point to CBD and CBD-A as being the most promising candidates, which makes your average high THC cannabis a relatively poor option in comparison. High CBD hemp extracts are 100% non-psychoactive and, obviously, do not come with the same social stigma as Cannabis.