If you have reason to believe that is the same Olof then indeed he does not have that son Jonas born in 1758 in the records up to 1760, so he came with his new wife Margareta. That might be true for several more of the children, including Stina!
If you can't track Margareta Olsdotter backwards, again I suggest following Stina's siblings forward in time to see if they get better data later than what Stina got.