I wonder what time exactly she gave birth? If she could get through transition and crowning without waking up family members in nearby bedrooms, I would think she could be quite stoic through hours of increasing contractions. Speculation: If she gave birth at 3am, for example, she might have been in her room, grappling with contractions from 8pm, and before that if the pains were milder and further apart, so she could have just battled through them, like a bad period.
I'm sure the birth was relatively quick, and she was "lucky" with the timing, that it happened at night when nobody was observing her, but I just don't take anything she says at face value. Saying it "just plopped out" without warning is another way of abdicating responsibility by not doing anything before it was born, and then not "having to" do anything after it was born, because she was pretty sure it was dead and really didn't try anything to revive it.