Hi Trevellian and a warm welcome to Rootschat
this is from Rootspoint - 1861 census - all born Illogan ,Cornwall and Catherines mother is with them
Broad Lane
Klogan, Cornwall
Household Members:
Abel Angove (60, Male)
Catherine Angove (48, Female)
Mary Ann Angove (20, Female)
William Angove (17, Male)
John Allen Angove (15, Male)
Ellen Angove (11, Female)
Catherine Allen (75, Female
So - I think you must be right in saying a little white lie on the marriage details - she would have been 25 when she married - not under 21 as you suggest - she may have been one of those ladies who "knocked off " a few years of her age

other members thoughts appreciated please

this looks to be Abel Angoves parents marrying in 1796 ( wife Elizabeth Uren - a nice easy surname to trace back )
https://gw.geneanet.org/snowmedic?n=angove&oc=&p=abel