Hi Danae

Need some more information to sort out John Callistor/Collister ( Always check for both). John and Margaret Crellin married 1/3/1821 Kirk German , both of this parish, children all baptised Kirk Patrick:
Thomas 11/11/1821
Maria 27/7/1823
Margaret 9/10/1825
William Crellin 30/9/1827.

This indicates parents of John maybe Thomas and Margaret. There is a christening 12/3/1802 in Ballaugh to Thomas Callister and Margaret Cannel.

John on 1841 census could be in St Bees, Cumberland, England aged 35-39 born IOM.

Margaret 39 with dau Margaret 15, son William 13 was with John Crellin 46-50, wife Elizabeth 50-54 dau Sarah 17-21 and son Edward 13 at Knockbreck, German. This is confusing, thought John Crellin was brother , but from next will appears her father , so age must be wrong.

The will of John Crellin 1853 of Knockbreck , German names sons Richard, Caesar and Edward and includes " Gives Twenty Pounds sterling to Daughter Margaret Callister to be free and beyond the control of her husband"

There is a family tree on Wikitree posted by Maxene Callister showing Margaret Crellin ch 30/6/1801 to John Crellin and Margaret Ann Mylchreest in German. (could not find on IGI)

On a Manxnotebook there is a will of Margaret Crellin 1837 that names children Edward, Caesar, Elizabeth, Eliza, Sarah and Ellinor and grandson William.

So it appears Margaret died around 1837 and John, Widower remarried Elizabeth Clucas , widow 19/12/1839 in Kirk German.

John Callister very common name on IOM , suspect you may have to check the possibilities - around 20 and find out what happened to each and every one to eliminate them.

David Dwyer
Sydney