I'm not sure if you have Margaret on the early censuses. I think this is most likely to be the family in 1841:
Graig Twrch, Cerrigydrudion, Denbighshire
HO107/1402/1/39/12
John Jones, 30, farmer
Dorothy, wife, 25
Margaret, d, 6
David, s,4
Anne, d, 2
All but Dorothy b. Denbighshire.