Catherine DUNCALF married John ROWSE at Plymouth Charles 1 Nov 1814. She was baptised at Plymouth Charles 16 Dec 1789, dau of Henry & Mary.
The John ROWSE buried in 1841 was buried at Plympton St Mary and was resident at Venton in that parish, so probably not yours. There was one buried at Plymouth St Andrew 9 Oct 1825.
John ROWSE was baptised at Plymouth St Andrew 1 Sep 1815, father John described as a cooper.
Catharine ROWSE was baptised at Plymouth St Andrew 25 Aug 1817, father John described as a cooper.
Mary ROWSE 22 Jul 1821 father John described as a cooper.
Henry Duncalf ROWSE wasn't baptised until 8 Apr 1834, said to be born 3 Sept 1824, address Gaskin Street, father a cooper.