Everything points to the correct marriage regarding the fathers of Mary and Edward and I have had a look at the Freecen 1891 census for the Williams family and Edward has a sister name Ada. Who George Henry Matthews is I have no idea.
Things go a bit haywire when it come to the 1901 census when Mary is living with William J Williams. North Parade,Camborne, is correct as Mary gave that address when she registered her mother's death. I purchased the death certificate.
For your records, this marriage took place in the Newquay Chapel, not St Columb Minor Parish Church
Newquay Chapel 7 Apr 1900.....WILLIAMS Edward John, 32, Bachelor, Plasterer of Newquay, father Edward John Williams, Plasterer = BEARE Mary Ann, 33, Spinster of Newquay, father James Beare, Tin Dresser by Banns. Both Signed. Witnesses: George Henry Matthews and Ada Williams