I am having difficulty tracing Sarah. There are no birth place/age matches and have searched Wales, unless I am missing her?
I have looked for Griffith, this is the only match so far I can come up with. Do not know if they are your people.
1861census
RG9/4322 Folio: 14 Page: 8
Reg district: Festiniog
Llanfihangely traethau
Address - Tydogadu?
Griffith Evans abt 1791 Llanbedr, Merionethshire, Wales Head Llanbedr, shoemaker
Elizabeth Evans abt 1789 Llanbedr Wife Llanbedr
Will try trace this couple back to 1851 see who they are with.
They are at the same address there is just the two again...he is a mason in 1851. I do not think these can be sarah's parents....because of age - sorry.