Dominion Energy Administrative Assistant interview questions

The interview was for an administrative assistant position. The interview was conducted by the administrative assistant, safety officer, and a field safety person. The interview was very laid back. Each person on the panel asked several questions, mostly pertaining to what if situations or experience situations. At the end of the interview I was walked out to the entry gate and asked "How old are your kids"? I never mentioned having children in the interview or anywhere else. It was very inappropriate for the interviewer to ask me that question and I did not even think twice about answering the question. I should have said "I don't remember saying that I had kids."