Catherine is showing Wick in her 1891 entry and an 1867 birth year, so Jean's 1871 census entry looks like it could well be her:
James Robertson 26, pastry baker, b. Airdrie
Catherine Robertson 23, b. Wick
Isabella Robertson 4, b. Glasgow
John Robertson 2, b. Govan
Address: 49 Commonside St, Airdrie
Regards.
Monica