I read this article, which appears to address many of the insensitive questions that mothers in general face very often.
What really struck a chord the most was this comment by someone called Chenome:
I have been both a working mom and a stay at home mom and have been insulted in both capacities. There’s always going to be someone questioning what you do or trying to feel better about themselves by putting you down. Do what you have and can do and don’t bother about what other people have to say.