Hi Ian, looks like you have a few leads to go on.
This ref looks like the second marriage for George. Maybe trying to trace Mary Lambert through earlier census to see if info matches on later census, may help confirm, also if both marriage certs match for info on George you can verify the 1841 census as yours. Also have a lead back to an earlier line on fathers.
Which if so, seems likely the death in 1848 of Ellen is yours also
Marriages Sep 1858 (only two on page)
Lambert Mary Lincoln 7a 689
Maw George Lincoln 7a 689
Good luck & happy hunting, and also a warm welcome to Rootschat

Cas