With ref. to Gnu's Reply 16 on p.2 of this thread -- viz
A possible on the IGI (and pilot) for [Sophia] Rebecca
Baptism 4 July 1824 Oswestry Rebecca Owen d/o William Owen and Rebecca
Not found anything worthwhile on a search for Tryphena - a few Ancestry trees but nothing much apart from marrying a Tanner and emigrating to Australia. Her death record in Malvern, Victoria only has her parents as unknown Owen.
I'm thinking that Rebecca's surname might possiibly be Mostyn
gnu
Added - A strange patron submission on the IGI
Rebecca Mostyn-Owen b. about 1777, Woodhouse, Shropshire
Parents - William Mostyn-Owen and Rebecca Dodd
-- the same secondary source as I cited above in Reply 30 ties Sophia Rebecca reasonably firmly into the Owen of Woodhouse family. But it does so via a
different page which is not properly linked to the Thelwall pedigree as a cross-reference in the database.
Following the link from there upwards to her father reveals the full list of her siblings -- 13 of them, including dates of birth. Of those in the house with (Sophia) Rebecca at Oswestry in 1841, Tryphena Owen is shown as b. 17 Oct. 1825, Rupert Mostyn Owen as b. 15 Nov. 1832, Julia Owen and Llewelyn Mostyn Owen as twins b. 4 July 1836, and Harriett Jessie Owen as b. 12 August 1838 (surnames repeated for the benefit of the search engines

).
If one clicks on the name of her husband Bevis on Sophia Rebecca's own page it becomes apparent that the source used for her marriage was Joseph Morris's 19th c. collection of Shropshire pedigrees, now kept at Shrewsbury Record Office.
(Morris has a secure place in my pantheon of genealogical heroes as the man who saved one of the best 17th c. pedigree collections focused on NE Wales, by making a painstaking MS copy of the Salusbury Book of Pedigrees in the library at Wynnstay just a few years before most of the house, including the priceless contents of the library, burned to the ground in 1858. His two-volume copy is now NLW Wynnstay MSS. 143-4 -- and I never tire of citing it!)
Rol