The 1851 Glamorgan census shows this family which looks like your Sarah
(census gives Sarrah)
2464 1851 CENSUS OF RHOS. REF.H.O.107/2464, E.D.7A.
Piece: 2464 Folio: 527 Schedule: 044
Address: PEN Y DRAMROAD
EVANS THOMAS HD M 38 COALMINER
GLA LLANGUICKE [LLANGIWG] (c1813)
EVANS SARRAH WI M 27 COALMINERS WIFE
GLA CILYBEBYLL (c1824)
EVANS MARRY DA U 12 COALMINERS DAUR
GLA CILYBEBYLL (c1839)
EVANS ELIZABETH DA U 8 COALMINERS DAUR
GLA CILYBEBYLL (c1843)
EVANS SARRAH DA U 6 COALMINERS DAUR
GLA CILYBEBYLL (c1845)
EVANS GWENLLIAN DA U 2 COALMINERS DAUR
GLA CILYBEBYLL (c1849)
On
http://freebmd.rootsweb.com this marriage is noted
Surname First name(s) Age District Vol Page
Marriages Mar 1867
Evans Sarah Neath 11a 545
Jones Howell Neath 11a 545
Send for a copy of the marriage certificate to confirm parents names
This site gives details on how to apply for a certificate and has a downloadable application form
http://www.statistics.gov.uk/nsbase/registration/certificate...If you send for a certificate please quote the volume and page number
I could not identify Howell in the census - if you get the marriage certificate his parents may help to identify him.