If you look at it closely you see there are only 4 letters. S (gamma), letter, r, letter. If you look at Larsdotter and Erik and compare the r(s) there to the middle letter of the mother's name they are the same. I can't think of another name that was common or even uncommon back then that started with an s and had an r in the middle other than Sara. If you look at the a in Larsdotter it's the same as what would be the a(s) in Sara.
I'll lave to look as some of the other entries around this record to compare tomorrow when I get to the library and have access to the records.
I'd feel better about Cnudsson if I'd seen other Cnudssons along the way. I've seen the odd Knutsson though and with seeing Cherstin/Kerstin and Carin/Karin throughout the records I suppose Cnudsson could work.