In this ancestry search result, there's a death year (1791) for the mother Cecilia Krok. If someone has a subscription and would like to check where the death year seems to come from, I'd be grateful.
So far I have not found a record for her death anywhere.
https://www.ancestry.com/genealogy/records/nils-gustaf-lundberg-24-230h8gv
Thank you both. I will search for her death in Karlshamn, maybe someone knows something that I haven't found out yet