Suicide is a very tough subject, especially in a situation like this. She was terminally ill and was given 6 months to live. I think that if she can talk and speak and still do things herself I completely think that was her choice. She didn't want to suffer anymore she wanted to die with dignity and you have to respect that. Yes, her family was obviously devastated but she's also the one with Cancer, not them. Although what if there was a miraculous way to treat it and she could get better? Did she wait long enough? Thats where it gets confusing.
I think suicide is very sad, it makes me sad to think that someone could feel like they have no other option than to end their life. I know suicide and this act are a tad bit different but very similar. Suicide is also a touchy subject because in the Bible it states if you commit suicide you will go to Hell and thats where it becomes a debate. I think if you are ill enough and would find peace with death that is your choice.