Frank your Majesty said:
Maybe her mother died and her father married an 18 year old, but then the father also died, so the stepmom married another 18 year old, and all of this within a year?In that case, the parents have to ask the kid for permission.
And of course, it is possible to end up with parents young enough to be one’s grandchildren.
Since this scenario could actually manifest with our current president’s family, it’s good to have the protocol worked out ahead of time.