given that the 1851 census was 31/3, a child born the previous November would be 4 months old. There are only 2 on the 1851 census that I can see, one in Trevethin, Monmouthshire and this one who may fit
Is Glan, Cwm, Flintshire HO107/2506 folio 54 pg 19
Frederick Edwards head mar 28 farmer of 160 acres employing 7 labourers b. Flintshire, Rhuddlan
Mary wife 25 b. Denbighshire, Gyffylliog
Mary Ann dau 4 b. Rhuddlan
John son 2 b. Rhuddlan
Thomas son 1 b. Rhuddlan
Robert son 4 months b. Rhuddlan
Margaret Roberts niece in law 15 b. Denbighshire, Llanrhaedr
+ 6 servants
marriage reg
Frederick Edwards march qtr 1846 Saint Asaph vol 27 pg 285 with Mary Roberts the only other on the page
change of occupation for Frederick by 1861
27 High St, Rhyl (parish of Rhuddlan) RG9/4296 folio 66 pg 8
Frederick Edwards head mar 40 joiner b. Rhyl
Mary wife 36 b. Denb, Gyffylliog
Robert son 10 b. Flintshire, Cwm
William son 8 b. Cwm
Frederick son 6 b. Cwm
Susannah dau 4 b. Denbighshire
Henry Cohen visitor 46 commercial traveller b. London
Likely baptism for Frederick in extracted batch C056711 for Rhuddlan
Frederic bp 11/5/1820 son of John Edwards & Susannah Hughes
1841 Pen y Bryn, Cefndu, Rhuddlan HO107/1412/26 folio 31 pg 6
Susannah Edwards 50 farmer
John 25
Anne 25
Robert 25
Frederick 21
Cornelius 15
William 14
Susannah 12
+ 6 servants