I've never done it, but it seems that there is a possibility to transfer miles if you can prove you are family members even if your family is not set up with Asiana.
https://flyasiana.com/C/KR/EN/conten...leage-transfer
I suppose that it depends in each country for the proof of relationship. In some European Countries, you have a family book.
Otherwise you could use the mariage certificate.
In NYS, it seems that the birth certificate is acceptable if it lists you. So maybe you can propose that to OZ?
https://www.tax.ny.gov/pit/letters/child-dependents.htm