I don't get all the different permutations. There should be two possibilities:
- 12 * 70 lbs. (if everyone on *G PNR gets the same allowance)
- 6 * 70 lbs. + 4 * 50 lbs. (if they don't get the same allowance)
Recent travel (personal witness) has indicated that the first is the case, and OP should be able to check 12 bags, each weighing 70 pounds, all free of charge.