Yeah, I figured the mother being both in her third trimester (with a countdown for being in labor) and in her second trimester was a glitch of some kind.
I searched my filesystem and found five lastException_*.txt files. I'm not sure how to tell which one would be from which glitch.
I don't think I selected TFB, but both parents were feeling pretty flirty and they were engaging in Woohoo without me telling them to. (Kinda like the way they sometimes check on crying babies, infants, and toddlers automatically without me telling them to.) And both of them are family oriented as their overall goal.
This may be less likely to occur now, just because caring for 4 kids (soon to be 5) is keeping them too tired for much Woohoo/TFB. Although the eldest is now a teen, and is able to help with the younger ones, so...