To those who didn't read the story related to the OP, the lady mentioned is terminally ill, she has an incurable cancer that will kill her in a horrific, painful, and miserable way within months. She decided that she would rather die on her own terms before her disease makes her life literally a living hell that will end with her death after months of suffering. I cannot fault her for not wanting to put herself and her loved ones through the agony of watching her pass in such a painful way.
I have watched a grandparent slowly die as their cancer entered their brain. They spent months in pain, forgot everyone they ever knew, and were at the mental state of a newborn child when they died. It was the worst thing I've seen, and I cannot fault anyone for wanting to avoid that type of death.
Suicide committed by someone not terminally ill is a tragedy, as it means that our society failed to get that person the help they needed to overcome their depression or struggles. The key difference being, the medicine exists to help people with depression and other things that lead to suicide attempts. That is difference between morally right and wrong. Making someone suffer only to face a horrid, incurable death, cannot be justified. Making someone suffer to face the chance of a healthy, happy life can pretty easily be justified.