Hi Mark,

The point I wanted to make was that in census reports we can't assume that the wife is the mother of the children of the family on account of the possibility of second marriages.

However, I think that doesn't actually matter as having followed the censuses through - and I'm ready to hear that I've got it wrong - I now think the Braddan John, son of Santon William, isn't the same person as your John who married Louisa. I'll show the two sets of families below, firstly the Braddan John in summary from 1851, (I've got the full versions if needed) then the German John working back from 1901 which you seemed secure of, with your known ancestor Eliza.

This John is consistently born in Braddan in 1846 and in agriculture:

(1851) John Callister s 5 scholar Braddan [s/o William & ?Margaret]
(1861) John Collister s 15 Farmer’s boy IOM
(1871) John Collister man servt un 25 Farm servant (indoor) Braddan
(1881) John Collister h m 35 Ag. Labourer Braddan [mar. to Sarah]
(1891) John Collister h wid 45 Ag lab Braddan

I couldn't find him in 1901.

The age of the John who married Louisa does fluctuate between censuses, even if the 1901 age is felt to be correct. Keeping the birthplace consistent at German makes some workable guesses for the fishermen in 1881 & 1871, but there are two alternative possibilities for 1861 & 1851 - if anyone can decipher the occupation for John Callister on the vessel "Catharine" in 1871 it might help point to whether he could be the son of Joiner Thomas Callister, or the Tailor son of William Callister:

(1901) 4 Merton Bank, Douglas, Onchan (dist 11) RG 13/5303 f.51 p.7 sch.43
John Callister h m 54 Flax bleacher German
Louisa w m 46 Patrick
Louisa d s 20 Pupil teacher German
William s s 18 House Painters App German
Ann d s 13 German
Joseph s 11 Braddan
John s 6 Braddan

(1891) No. 16 Cronkbourne, Braddan (dist 3) RG12/4690 f.38 p.13 sch.53
John J Collister h m 40 Flax Bleacher German
Louisa J w m 37 “ Spinner Patrick
Eliza Ann d s 18 “ Winder German
Sage d s 16 “ Spinner German
Katie d s 12 Scholar German
William J s s 8 “ Braddan
Joseph Hy s s 1 Braddan

(1881) Poortown Road, German (dist 3) RG11/5596 f.107 p.16 sch.78
Louisa Collister h m 25 Fisherman’s wife (husband at sea) German
Eliza d 8 Scholar German
Sage d 6 “ German
Catherine d 2 German
Louisa d 6mo German

(1881) 48 “Maggie Maddrell” Fishermen at Kinsale Mackerel Fishing, 1, German RG11/5609 f.66 p.37
John Gill m 29 Fisherman
John Callister m 32 Fisherman

(1871) 32 “Catharine” (Vessels) RG10/5771 f.209 p.18
Thos Gorry m 48 (Residence) Peel Mariner
Jos McArd un 18 “ Mariner
Phil Gorry m 57 “ “
?Caesar Gorry un 20 “ “
Rich Coffee un 18 “ “
John ~~ un 22 Patrick “
Dav Fargher un 20 ?Douglas “
John Callister un 24 German ?J~~~

EITHER:
(1861) Kirk Patrick St, Peel, German (dist 2b) RG9/4428 f.63 p.14 sch.198
Margt Skelly h wid 65 No occupt Peel
John Callister gson 16 “ Peel
Esther gdau 12 Peel
Walter gson 9 Peel
Beecher gson 2 Peel
&
(1851) Kirk Michael St, Peel, German (dist 2a) HO 107/2523 f.147 p.14 sch.56 [Catterter]
Thomas Callister h m 45 Joiner Peel
Margaret w m 31 Peel
Mary d 9 Peel
John s 5 Peel
Esther d 1 Peel

OR:
(1861) Charles St, Peel, German (dist 1B) RG9/4428 f.15 p.21 sch.129 [Collester]
William Callister h m 50 farmer of 36 acres German
Emily w m 47 German
John s un 17 Tailor German
Caesar s un 12 Scholar German
&
(1851) Close e Garey, German HO 107/2523 f.202 p.20/21 sch.74 [as DJD]
William Callister h m 41 Landed prop. Farming 35 acres German
Amelia w m 39 German
Maria d u 19 Household German
William s u 18 Farmer’s son German
Louisa d u 16 Household German
Elizabeth d 12 Scholar German
Ellinor d 10 Scholar German
John s 7 German
Casar s 2 German

Obviously, there are quite a few John Callisters/Collisters out there, and someone will probably prove I've made some errors in linking these together, but I feel fairly confident about the Braddan born John.