(Even though I am a licensed attorney, the following is not legal advice, just a comment.)
I am most concerned about the comment that your friend should not have any more children. That sounds like parenthood discrimination, which is an actionable form of gender discrimination under Title IX (and since your friend is a graduate student, he's probably an employee, which would bring it under Title VII as well), and maybe any number of state laws.
I would agree in general, but the comment may lack context -- such as if it came in response to the student's repeated reluctance to schedule the required oral defense owing to what the OP termed "family obligations."
For example, if the student actually said, repeatedly, that the student's children's schedule took priority over the scheduling of a requirement for the degree, complicated by the schedules of five faculty members, well . . . we need to know more about what actually was said on both sides, about how long this has been going on, etc.
I have endured a similar situation, in which the student communicated that it was the faculty who ought to change their schedules for the student's children's schedules (and, I would note, many of the faculty on the committee also had young children but did not raise this as a reason and had offered many available times).
On the other hand, when I was trying to schedule my doctoral defense, I had a committee member who would not meet on Fridays -- the only day that I was not teaching, ABD, several hours away. When I was only weks away from dissertating or being fired by my dean, my advisor finally stepped in and got the defense scheduled. (And, of course, the recalcitrant committee member turned out to not have read my diss., anyway.)