Yeah, that's a little complex but seems doable. Basically just think of it as a monster with multiple heads and limbs. Each face should be tagged as a different view, so maybe frontal for the girl and left quarter for the dad, so the facial features will work in each. I'd probably do something like:
Before getting too deep into artwork, I'd make a stick figure / basic circles & rectangles version to make sure the idea works. I do that a lot for anything out of the ordinary.
Question, though- is it possible to tage frontal for the girl and left quarter for the dad but still have each of their heads be able to turn left profile/quarter/frontal/right profile/quarter? I guess I can play around but trying to understand how the tagging works.
Oh, in that case you probably want to give each head its own Face, Lip Sync, Eye Gaze, and Head Turner behaviors. So yes, it's possible, just more manual behavior adding.