I am not a mother myself, but my friends who are mothers say other mothers can be very judgmental of the way they raise their children. One friend can't breastfeed due to breast reduction surgery, and other mothers still give her a hard time for using formula. I am in no position to judge of course, but I don't think other mothers are really either.
I'm sorry about your friend, and I agree that raising 5 kids is work. I can't imagine doing that.