There's a lot of people that are unaware and completely oblivious to the repercussions for their actions. They lack common sense, knowledge, empathy, sympathy and courtesy. They have no regards or consideration for other people's feelings, health or hardships. That is one of the only things that demoralizes me in my current 18 years of living.
Thankfully there was no severity to your relative, and I hope that continues. Tell her to take it easy.
I agree with you completely, don't take anything for granted. Whether it be a relationship, a situation with family, friends or an occupation or anything in general. Life is a virtue, time is of the essence. C'est La Vie.