There is a Catharine Carnegie listed for 10 January 1814 at Bervie in the The Church of Jesus Christ of Latter-day Saints records.
Further,
Checking the census, post 1842 marriage at St Clements,
1851, Aberdeen, Old Machar, Catherine Allan (27)
1851, Aberdeen, Aberdeen, Catharine Allan (36) Note the spelling is of that listed in the Bervie birth of 1814.
1861, Aberdeen, St Nicholas, Catherine Allan (45)
1871, Aberdeen, St Nicholas, Catherine Allan (52)
1881, Aberdeen, St Nicholas, Catherine Allan (64)
Regards
Malky