What is the best solution for caring for a sick grandmother, and which of her children is obligated to care for her under the mentioned circumstances?

Taking care of an elderly mother is the responsibility of all her children, male and female. If they are unable to care for her directly, they must hire someone to serve her. If her sister can do so, she is more deserving than others, and her wages are binding upon all the children, each according to their ability. The children must compete in showing filial piety towards their mother and serving her, due to the virtue of honoring one's mother and her immense right.