This can have a big effect on a child, or young adult as you are no longer seen as a child to that elderly family member, your now taking on more of a parenting role and are forced to make alot of the decisions and take on bigger responsibilites. It can be positive in a way as it can create a stonger bond between the two of you.
In my late grand mothers last days, after she had chemo theropy she was very weak. I was only 12. It was the summer time so I was out of school. I looked after my grandma while my uncle was at work. I just changed her feeding bag, helped her get around. Little things like that. I was only 12 at the time, so I wanted to be outside playing, but now that I look back on that, I was glad I was there. Kids dont understand u know?