1841 census in Montrose, Gibson Place is a John Thom, carpenter, b. 1786, Jean Thom b. 1786 and a daughter Jean Thom b. 1826
1851 census in Montrose, 13 River Street is a John Thom, shipwright, b. 1782, daughter Jane Thom, b. 1825 and a grand daughter Anne Robertson, b. 1850
The names Jean/Jane were often interchangeable ... record keeping was not statutory in Scotland until 1855 so before then there is not so much to go on. It doesn't look as if there is a christening record for either 'your' James or the above daughter Jane/Jean.
I can't find any other records for these people - can anyone else?