what's wrong with asking how many kids you have ? sounds like a pretty benign question to me and maybe he/she was just trying to learn more about you outside of work.
look ...it's the same for programs as it is for applicants... when you get your interviews and even before you start going to them, you always have some kind of general idea on how you would rank them ... not uncommonly, that list changes after interviewing. Same for programs, they have a general idea on how each applicant would fall on their rank list (high, mid, safety net..etc). but it also happens that they interview somebody who on paper they think is a superstar but he turns out to be a sociopath or douche or somehow nobody likes him during the interview so he gets knocked down to the bottom of the list or maybe not ranked at all. on the other hand, they might interview somebody who barely got the interview invite but he expresses himself well during the interview and seems like a good fit for the program and everybody likes him that day and he is now ranked to match.
how often does that happen? I have no idea but I think it's variable each year and for each program.
