I plan to book a trip for my in law from CGK to SFO. I plan to use Cathay route since it has lowest fee $935 HKD although it requires more miles (90k). Anyway, her Amex is only 81k. I have 9k to transfer. I understand you can't share MR points directly. I have added her AM account on my Amex and also ad her to authorized user.

My question is, when I am ready to transfer 9k points to her AM, do I use my Amex card, or do I wait for the new authorized card to come in the mail and use that instead as card verification?