Thats a very tough question. I guess it would totally depend on the children’s situation. There are a lot of factors to consider. “Do they have ample space and the needed previsions to care for them? Do they have the necessary financial ability and time for what is needed?” If the answer is yes, by all means move them in and help your family that supported you for many years.
You shouldn’t have to think twice about that when they’ve taken care of you until you could take care of yourself. In my opinion there is nothing to think about where there’s a will there’s a way.