Dear Sarah,
You care about your cousin, so, of course, you're worried. Find out more about your cousin's illness and the kind and length of treatment expected. That way, when you visit your cousin at home or in the hospital, you will understand what is going on. You might also ask your cousin's parents whether there is something you can do for them while they're busy with your cousin—maybe taking care of their pets or doing chores around the house. It's always better to do something helpful than to just sit and worry. And remember that it's okay for you to have fun while your cousin is sick.