How to handle sexist questions toward a faculty job candidate by other undergraduates? I am an undergraduate in the U.S., and my university is currently interviewing for an open faculty position. The department arranges lunches with the job candidates and current undergraduate students, where we can ask the candidate questions and get to know them. Students fill out an evaluation of the candidate following the lunch (which is in theory taken into consideration for the hiring decision). However, the atmosphere of this meeting itself is quite informal and conversational.

Two of the candidates are currently expecting a baby. The male candidate said on their own that he was expecting a baby. One fellow undergraduate specifically asked the female candidate (in front of 20 other undergrads) if she would be able to balance a new baby and the job at the same time. However, she did not bring this up with the male candidate, who is also expecting a baby. We met with the male candidate first.

As a fellow undergraduate, how could I respectfully address this?
There are two issues at play here depending on if you are formally part of the hiring process.

If you are formally part of the hiring processing asking questions about the family life of a job candidate, man or woman, is treading on thin ice. Even if the information is not meant to be discriminatory (e.g., as a search chair you might want to be helpful and look into spaces in the university nursery), it is just a topic you do not bring up. As a formal part of the search committee, it is reasonable to mention to the person who asked the question that family life is a topic to avoid. You may also want to mention it to the search chair so they can be prepared for any claims of discrimination.

If you are not formally part of the hiring process (e.g., potential faculty tend to like to meet students), the issue is difficult. It is perfectly reasonable, and non-sexist, for a female student to ask a female applicant about work life balance. It is a topic that a female student might have questions and concerns about for themselves going forward. Of course it could be a sexist remark to intentionally sabotage the candidate. Note that any combination of student and applicant sex could be non sexist (a male student may want to understand how their potential wife might would handle the work-life balance and a female student might want to know about how a husband would handle it). Given that, I would not raise it with the student that the question was sexist. Rather, I would point out that while the point of meeting with the candidates is to give undergraduate students exposure, that the students should be welcoming to the applicants and try and put their best foot forward. Asking about touchy subjects is not in the best interest of the department.