Thank you for your response. One possible reason you can't find the family in 1841 Census is that the last two siblings, Isabella and Ellinor are indicated to have be born in Ireland in 1842 and 1845 respectively.
The Cath Pierson you mentioned buried at Rushen could be the mother as her burial date fits in with Jonathan snr being a widower in the 1851 Census.
As for Ellinor (also known as Ellen) she married Patrick Watterson in 1863.