Fever can support the immune system's attempt to gain advantage over infectious agents, such as viruses and bacteria, and it makes the body less favorable as a host for replicating viruses and bacteria, which are temperature sensitive. Infectious agents are not the only causes of fever, however.
Your sister's grandson is your great nephew. You are his great aunt (if you are a woman) or his great uncle (if you are a man).
This is excusable, as the granddaughter is a 3-year-old child, but I think that the story shouldnât have mostly been about her. At first glance of the title, I thought the story would have been about an Irish person or something, but I was very surprised to know that the narrator/main character is a Chinese immigrant.