In English, you can say
How are you?
How is she?
How are you doing?
How are they doing?
...for various situations.
It something important or unfortunate happens, it’s a little more common to use “How is (someone) doing?” This might be because “doing” suggests that the situation is temporary and that it might change. Also, we say “How are you?” or “How is (someone)?” so often that the question not as meaningful. Many people answer “good” or “fine” even if it’s not true.
So if your friend Ruthie got into a bad car accident, you can call her family and ask:
I heard about Ruthie-- how is she doing?