Taylor....the 3 months time line is not written in stone, it's a "likely" prediction only. For all we know your mother in-law will be talking about this cancer for quite a while to come. We experienced it on the board many times over in that patient's outlived this cancer for years and are going strong. to this date. Take a look at Cathy's (jathy1125) posting.
The issue of Quality of life vs. Quantity of life ultimately is made by the patient. Current treatment options offer "hope" but do not guarantee individual success. A cancer diagnosis most often translates into loss of power over one's life, however the decision of how to address the disease is in the individual's hand.
If indeed your mother in-law seeks the recommended treatment then she doesn't give up the power of either continuing or abandoning the treatment.
It's unlikely for any physician to recommend Cannabis. It's been studied and proven to be successful in many ways, but physicians can refer to any data derived from clinical research studies, which in turn set's the gold standard of patient care. For our cancer as well as any other cancer we can't refer to one single outcome of survival with Cannabis.
From a personal standpoint I strongly believe for cannabis to have a role in all areas of healthcare. We are noticing an explosion in research into the healing properties of cannabis and soon will have clear data to look back on.
My two cents.