If these are Charles Bettens and Anne Waldron married 1 of July 1815(as suggested on profile, there are three baptisms of children in Calstock. (From Cornwall OPC)
James bapt 28 Sept. 1815 bur 3 Oct 1815
James bapt 3 Nov, 1816 (you have him)
Maryann Pasco?(transcriber added question mark) 4 April 1819)
These are also on free reg (easier to cite as they provide a citation generator.)
Cornwall : Calstock : St Andrew : Parish Register : "Parish Register" database, FreeREG (https://www.freereg.org.uk/search_records/5817db29e93790ec8b45c1fc ) viewed 11 Apr 2024) baptism Maryann Pasco Bettens 05 Apr 1819
Could only find the baptism of Samuel in St Hilary ( 1 June 1834)
But Thomasine married a John Hosking in 1856 and Charles is named as her father.
Cornwall, St Hilary : St Hilary : : "Parish Register" database, FreeREG (https://www.freereg.org.uk/search_records/5817be02e93790eb7f7cce03) viewed 11 Apr 2024) marriage John Hosking to Thomasine Bettens 14 Jun 1856
Edit: This could be Ann's baptism
Cornwall : Calstock : St Andrew : Parish Register : "Parish Register" database, FreeREG (https://www.freereg.org.uk/search_records/5817db7ae93790ec8b46788e : viewed 11 Apr 2024) baptism Ann Waldern 25 Jan 1795