I think back then people had to wait a year before divorce was final; then the march 16 1965 would fit the timeline.
final decree dated March 20, 1964
So as you can see, the final decree was dated March 20, 1964, so the marriage date of March 5, 1964 could NOT be correct, and as she applied for the divorce in January, there was no 12 month waiting period involved.
There is a discrepancy however, the final decree shows an earlier date but it wasn’t signed until the 20th. I’m not a lawyer, I can’t tell if she would have been able to marry 15 days before the judge signed the decree nisi.