Here are some other children's baptisms, oddly it says Sarah is the 5th daughter too

Ryton Holy Cross
29 Dec 1805 Sarah Urwin, of Crawcrook, born 15-Oct 1805, 5th daughter of John Urwin (wagon wright, native of Lanchester) by his wife Mary nee Cowen (native of Washington)
Ryton Holy Cross
12 Jun 1808 George Urwin, of Crawcrook, born 24 Mar 1808, 3rd son of John Urwin (wright, native of Lanchester) by his wife Mary nee Cowans (native of Washington)
Gateshead St. Mary
21 Mar 1819 Esther Urwin, of Gateshead, child of John Urwin (enginewright) & Mary
Gateshead St. Mary
18 Mar 1821 Esther Urwin, of Gateshead, child of John Urwin (enginewright) & Mary
It does say that John was a native of Lanchester, and Mary a native of Washington, have you tried searching the Durham diocese Bishops' Transcripts, free to view on
http://www.rootschat.com/links/076g/ just click on Durham, then Ryton, Lanchester, etc. These are not complete and not indexed, but as I said, free, and well worth trawling through
Barbara
