Let's start with John Jenkyn Quick.
First question - did John Jenkyn Quick (bp. 1783) survive through 1851?
Deaths Sep 1844 (99%)
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QUICK John Jenkin Penzance 9 135
Deaths Jun 1883 (92%)
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QUICK John Jenkyn 64 Penzance 5c 200
There were five QUICKs with the christian names of John Jenkyn who need to be considered (at least one other born and married later).
1. s/o Richard and Honour bp. 1783
2. s/o William and Elizabeth 1813-1815
3. s/o William and Elizabeth bp. 1819
4. s/o George and Mary bp. 1820
5. s/o John Jenkyn and Martha bp. 1844
And there are two marriages for John Jenkyn Quick that can be considered with the above.
The 1883 death must be either 3. or 4.
5. married Eliza Jane SISLEY at St Ives in 1870
4. married Martha STEVENS at St Ives in 1844
4. was still alive in 1881 but had died before the 1891 Census so it was he who died in 1883.
The 1844 death therefore is either no 1. or no 3.
I cannot find 3. in any Census but I have him labelled as a 'fisherman' which indicates I have further information on him somewhere.
At this point I am not prepared to say which of the two died in 1844 so I will now work on the details from the 1841 and 1851 Census.
In 1841 John and Betsy had Elizabeth POLMEAR, age 15, with them.
In 1851 they had grandaughter Clara POLMEAR, niece Mary Ann WOOLCOCK and grandsons Daniel and Henry D EDWARDS with them.
While I am still checking things - just take a look at this from the 1861 Census index on you-know-where:-
John Quick abt 1836 Schwarzburg-Sondershausen, St Ives Lodger St Ives, Cornwall
View Record
John Quick Thomas,
Alorvina abt 1852 Schwarzburg-Sondershausen, Zennor Son St Ives, Cornwall
I had a look at the original image and there is know son whatsoever of Schwarzburg-etc... on that page!
Thought that might amuse you during the interval ... ;D
Right - some conclusions.
First of all - I am not prepared to say definitely that John was actually John Jenkyn QUICK and therefore uncle of Charles and his brother Thomas who was also in the same abode in 1841.
Circumstantial evidence suggests that it is Charles' uncle but the absence of any record of him with the second name or even just second initial places doubt in my mind.
It looks like both John and Bestsy had died prior to the 1861 Census and although there are a number of John Quicks dying between 1851 and 1861 in the Penzance district none of them was recorded as John Jenkyn (or J) Quick.
We really only have that 1844 death for John Jenkin QUICK and I can still find no sign of the son of William and Elizabeth who was bp. in 1819.
Now the 1851 household included more relatives than you recorded in your query.
We had as follows:-
Clara POLMEAR, 19, grandaughter
Daniel EDWARDS, 18, grandson
Henry D EDWARDS, 15, grandson
Mary A WOOLCOCK, 19, niece
From these I was able to determine conclusively that John's wife was Elizabeth POLMEAR and that she was a widow when she married John QUICK.
Henry POLMEAR m. Elizabeth NOALL 18th August 1805 at St Ives
Children:-
Henry bp. 20th April 1806
Mary Ann bp. 15th January 1809
David bp. 8th May 1812
Betsey bp. 15th July 1814
John bp. 26th September 1823
Henry POLMEAR was buried at St Ives 31st December 1823 age 39.
Henry m. Clarinda FREEMAN 8th February 1829 at St Ives
Clara POLMEAR bp. 7th September 1831 St Ives
Mary Ann m. Daniel EDWARDS 18th August 1830 at St Ives
Daniel EDWARDS bp. 6th June 1834
Henry Daniel EDWARDS bp. 3rd January 1836
Those are the grandchildren and it is obvious they are all Elizabeth's grandchildren.
Mary Ann WOOLCOCK bp. 30th September 1831 at St Ives d/o Anthony and Margery WOOLCOCK.
Anthony WOOLCOCK m. Margery NOALL 26th December 1818 at St Ives
And there is the niece.
So Elizabeth and Margery NOALL were sisters and it appears they were the children of Peter and Mary NOALL.
** I need Cornishmaid to clarify this **
Peter NOALL m. Mary HARRY 4th August 1774 at St Ives
Amongst there children were:-
Elizabeth bp. 20th May 1781
Padgey bp. 1st December 1793
Padgey was, in fact, Margery and this seems to have been some sort of nickname for girls named Margery.
So there is everything I can tell you.