"Eligible family member" is the main sticking point.
If QFF finds out, either of you or your friend's account can get locked.
What I would do, if I were you, and if you have WP/P1 status with QFF, and once our borders open, is that you and him or travel together, and you get to invite him or her into a QF international lounge, or you fly the same QFF flight as him/her, and get him/her preferential seating.
Transfers of points, is a grey area, and people have gotten their accounts locked, or "fingers burnt".
Claiming someone is your "cousin" might work, or might bring up some ref flag in QFF somewhere, and your account gets locked.
Best of luck, ideally, I would not do the transfer.
Use of your QFF status, when you both travel together, yes, but transfer of points, I wouldn't.