the 1841 census for Arbory would only seem to indicate 2 Thomas Cubbon's - one third son of Catherine & Thomas - the other 10 year Thomas is at the adjacent entry associated with two older females (mother & daughter ?) - other thomas cubbon/cubbin s are associated with Rushen or Malew -
Though I can find the family in Arbory in 1851 Thomas appears to be missing - this might well fit with a sea-faring job (see my comments in another answer re Peel fishermen being away in 1851) or it may indicate that this thomas was dead - however there do not appear to be any other Thomas Cubbon's of the coreect age in 1851 in arbory