What you do is go to the GA and tell her that your children have never flown First and you (as a treat) wanted to swap your seat in F with their seat. If F is wide open some GA's will give your seat to them, then suddenly give you F too.

Getting another in F depends on your willingness to give up your seat and having the right GA

Might get you 2 upgrades.

You could also do the "Mother-in -law" trick. Joke about you have to give your seat to your MIL and roll your eyes and offer your seats to swap.