Alan, in your first message you wrote "Thomas Cottier who married Mary Lawson at Braddan on the 22nd June 1833, we believe they emigrated to New York about 1837 were we think Thomas died...".
The IGI has extracted entries for the baptisms of children of this couple in 1845, so they must have returned to the IOM by then (and Thomas must have been alive until at least 1840).
1. CATHERINE LAWSON COTTIER Christening: 01 JUN 1834 Saint Mathews, Douglas.
LDS film number: 0106718 [1718 - 1849]
2. MARY ANN COTTIER Christening: 01 JAN 1836 Saint Barnabas, Douglas.
LDS film number: None pre-1849 given for St Barnabas. Someone might look for you in the MM?
3. MARTHA MATILDA COTTIER Birth: 28 MAY 1839; Christening: 12 FEB 1845 Ballaugh.
LDS film no. 0106707 [1607 - 1849]
4. THOMAS LAWSON COTTIER Birth: 20 DEC 1841; Christening: 12 FEB 1845 Ballaugh.
LDS film no. the same as for Martha.
This film would be well worth looking at to see whether any comments are made about the family and the late baptisms.
Sue