The Thomas Stalker + Catherine were still on Island in Ballaugh in June 1841 with 4 children (assuming Edward was their eldest who is in Lezayre) - Edward Stalker is shown as son Thomas Stalker + Cath Lord or Cleator, - the IGI shows indeed 8 children (+ ninth - the 1st William died) most as children of cath lord.
Thomas jnr is not with them - however there is a Thomas Saulter (age 35 which doesn't really fit with a 1813 christening and possibly is not him) at the Barracks in castletown.
This Thomas Stalker + family are absent from the 1851 census but Edward is still on the Island in 1851 with their surviving child but not is seems in 1861.

Thus if they emigrated in 1841 they were cuting it fairly fine as travel in the winter months wouldn't have been much fun - thus I would have expected them to depart by early august at latest giving arrival in New York in Sept.