It could well be her. I can't find a marriage bond for Thomas Edwards and Anne Williams, that may have helped.
By the way I can confirm that Elizabeth Griffith was born at Hafod y Wern Llanfihangel y Traethau in 1847 to Robert and Jane Griffith nee Williams. This backs up the will of William Williams of Rhosgill in 1847 which states that his grandsons Robert and John Edwards (sons of Jane by her first marriage to Richard Edwards) were living at Hafod Penrhyndeudraeth at the time.
What is interesting here is that the daughter is Catherine at Llys Patric in 1851 and Elizabeth in Bangor High Street in 1861. Robert Griffith and all three daughters, Laura, Jane and Elizabeth are in Bangor High Street (255 from his will in 1868) and Robert is widowed. I can't find a burial for Jane in Abererch or Llanarmon so I think she may have died in Bangor.
regards
David