ghSMART Executive Assistant interview questions

This was hands-down the weirdest interview I have ever done. This was the 2nd round of interviews, after an initial 30 min phone screening. The 2nd interview was scheduled to take 1 hour. The first question the interviewer asked was "What are some of your strengths at work?" which I answered in detail. Immediately after that question, she asked "What are some of your other strengths?" which I attempted to answer, although I felt awkward being asked the same question twice in a row. Predictably the next question was "What are some of your weaknesses at work?" which was again followed by the same question - "What are some of your other weaknesses?" At this point, the interviewer told me that she was sensing my discomfort with the nature of the questions, and I explained that the questions seemed repetitive. She said the repetitive questions were part of their process, and if I make it to the next round of interviews I should expect a 3+ hour 'deep dive' interview session with questions relating to my childhood, my parents, and my family life. At this point I became extremely uncomfortable with the interview process, because I have never been asked to elaborate on any personal details for an administrative role. I told the interviewer that I felt questions like that were inappropriate and invasive, and she responded that she had never received any feedback like that before. Given that ghSMART is a privately owned company, this interview raised major concerns surrounding privacy and equal employment opportunities. What is preventing the ghSMART recruiters from blanketly declining anyone who comes from a difficult childhood? And more importantly - why would they ever need to know that information? What exactly does my mother or father have to do with my ability to perform an administrative role? I considered this interview a blessing overall, since it saved me from what I can only imagine is a completely un-hinged 3-hour long 3rd interview. Maybe in the future they can just call my therapist directly and save me the time.