In the BLAIR to BAMBER marriage both parties were about 17 years old.
In Australia someone would need to give permission for such young people to marry and this would be recorded on the certificate.
Was this not an expectation in the Scotland of the time?
No. Parental consent was not required - this is the reason why Gretna Green became famous as a place to elope to, because it was the first place an eloping couple arrived at after crossing the Border, and they could get married there without it.