Continuing from William's very good-looking lead, you will find Deborah GILL (later HUGHES and possibly nee JONES) enumerated in Holywell in 1841.
HO107/1413/5, Folio 36, Pg16, Holywell, Hundred of Holywell
Deborah GILL/GILE/GILS age 35 (I think it actually may say GILS) with 4 children in house: children: Elizabeth 12, twins Thomas & Henry 9, Maria 6
The twins are enumerated as NOT born in Flintshire.
The children with Deborah & John HUGHES 1851 at HO107 / Piece 2227 -Folio 373- Pg21
are: Thomas 19, Henrery 19, Maria 15 or 13, Theresa ( the youngest with a single digit age but age is obliterated by checkmark thru it.) Also noting, the twins are NOT born Flintshire, but rather Manchester, as is Theresa. And the visitor in the house (visitors are very often relatives) is John JONES Blacksmith b Holywell . I think he is 56 not 36, and also John Hughes, could be 56 also - I think this enumerator's 3's elsewhere are quite different from his 5's.
On IGI: the Twins: Thomas GILES and Henry GILES are shown born 11 Oct 1831, baptised 18 Oct 1831, Parliament Street Saint Davids Wesleyan. Parents: William GILES and Deborah JONES
So re: 1841 family in Holywell :
missing from the household in 1841:
Son WIlliam born abt 1837 - but his could be the death recorded 1838 on BMD.
No IGI entry for an Elizabeth GILES born abt 1829, (and she could be married by 1851)
No evidence they had a daughter Sarah GILES born abt 1830. (could Elizabeth be Sarah using a middle name in one or the other Census?)
(according to IGI daughter Ann apparently died 1830 - abt 6mths after she was Christened)
What do you know about Sarah's Aunts as in 1851 - there are two of them perhaps, as it seems Sarah's Aunt Mary also has her (Mary's sister) in the house too: (though of course it could be sister-in-law):
At Old Quay Street 1851 - all born Greenfields - HO107/ Piece 2500- Folio482- Pg14
Head: widow Mary OWENS 53, Pauper
Daughters: unmarried Mary 20, Grace 16, and Elizabeth 14
Niece: unmarried Sarah GILES 21,
Sister: widow Elizabeth EDWARDS 55,
And what do you know of Sarah and her household in later Census, when she is perhaps married? Is her age and POB consistent throughout? If you have her marriage certificate, who were the witness?
Cheers

AMBLY