Why "have been" was used here? What does it mean?
"Have been" (present perfect continuous) is used here because she is describing an action that started in the past, and has continued to the present. Here, her family started staying home in the past, and they are still staying home in the present. Here are some examples of how to use "have been" to describe something that started in the past, and has continued to the present: Ex: I have been reading a great book. Ex: She has been doing her job for two years. Ex: He has been busy since he started college.