It would go to you, as flyer.
But you would need min 5000 VFF points to then transfer the points to another family member.
If you had put in receipient details before the flight, the points would go to the receipient.
My parents (mum pools her FB points and SC to her VFF account), then it comes to me, as they don't fly that much anymore, but she does a lot of Coles shopping.
I fly VA so the flying part of points and SC comes to me, but the Coles (FB points and SC), go to her first, then to me.
Best to put in receipient details before a flight, now you have to collect 5000 VFF and then transfer that to your nominated family member.
Edit: hmm, haven't tried the "trick", but Jedi_sith, have you done it, or is the OP a what if "presupposition"?
Granted as I mentioned, I have not done it, but would have thought you needed to do it prior to flight to take effect, then take flight and then points go to your receipient, or if after flight, the points and SC would go to you first as flyer, then when you have 5000 VFF points and SC, it then goes to your nominated receipient.