What (if anything) can one do to help someone who's in denial? (See details)

A friend of my mother’s has just received a diagnosis of ulcerative colitis, which I had for the past four years. She emailed my mom, knowing that we are familiar with the disease, looking for some support.

This is a disease that has cyclical periods of activity and remission; this woman just got out of a several month long flare up and is currently asymptomatic. In her email she told my mom that she will not take any medications for the disease. Her plan is to “hope that it won’t come back,” which isn’t even really a plan.

If she won’t take medication and it does come back, her options are dietary treatments of dubious effectiveness or surgery.

I know where she is mentally right now because I’ve been there, and there is a long process that one has to go through in realizing that this diagnosis usually means making some sacrifices, and that hoping for the best isn’t a useful plan in the event that the best doesn’t happen. I don’t want to be a rain cloud or doomsayer, but I also feel very uncomfortable not sharing what I know, knowing that she has the potential to get very, very sick. Should I just mind my own business?