Hi Ken,
first I must give You the right birth-dates and birth-parishes for Jonas Nilsson and Sara Nilsdotter. They were both born in Döderhult parish, Jonas was born 1792 April 15 in Dövstad, his parents were Royal Marine Soldier Nils Lustig and his wife Stina Persdotter, Sara was born 1794 March 19 in Flathult, her parents were Shoemaker Nils Gabrielsson and his wife Maria Jonsdotter (Döderhult C:4 page 114 and 146). Jonas and Sara were married 1815 June 24 in Döderhult (Döderhult C:3 page 128). Jonas and Sara had these children (except Gustaf Peter): Kristina Maria born 1816 April 15 in Djupeträsk Döderhult, Nils Magnus born 1818 March 31 in Djupeträsk Döderhult, Sven Erik born 1820 January 23 in Djupeträsk Döderhult, Karl Johan born 1822 August 25 in Ålebäcken Åserum Mönsterås, Anders Fredrik born 1829 February 1 in Sporek Döderhult (but the family lived in Rastorp in Misterhult parish and according to the household register Anders Fredrik was born in Misterhult parish) and Greta Sofia born 1832 October 10 in Ekelund Rastorp Misterhult. You can find the family first in Döderhult AI:2 page 234, they moved to Mönsterås parish 1822 but there are no household registers in Mönsterås parish from the 1820s, they moved from Döderhult parish 1828 to Misterhult parish and You can find the family in Misterhult AI:3a page 161 and in Misterhult AI:4a page 154. 1833 they moved back to Döderhult parish and You can find the family in Döderhult AI:4 page 621.
With best wishes
John