I would not worry about repeating the same question: if interviewers have the chance to talk each other about you they will not touch for sure your final question.
Questions about interviewer experience are always great, showing your curiosity in her motivation and expertise. If you have the chance to know before the name of the interviewer (you can ask it to HR the day before or discovering it in the waiting room), look at her LinkedIn profile to develope some tailored questions (e.g. about the MBA, the industry or practice specialization, etc.)
I also recommend you not to make questions about the firm that you can easily find online or through friends/other candidates (e.g. clients of the office, projects, typical workday, international opportunities, client exposure, your role, numbers of the office, ...).