I am not sure what is the underlying rule for when the use of “it” is appropriate and when “he / she”. Consider the following two examples:
- There is a lady at the door. It is my aunt.
- Do you know the lady with the hat? Yes, she is my aunt.
My choice of “it” vs “she” is based more on a feel rather than a rule and my examples could be wrong. There is a related post which explains that “it” is used as an expletive, but I am not sure whether that is a full answer in these cases. Could someone please explain how to analyze the options?