There are a couple of confusing details in your notes. First, you mention a christening in 1800 of Sven Pehrsson, born to a Sven Pehrsson who was himself born in 1800. I think this is the same individual mentioned twice, and that the note was actually meant to tell about Sven's and Sigrid's son (as Sven and Sigrid were born only two years apart, I assume they are the parents here). That son is perhaps Pehr Svensson born in 1821, mentioned in your third note?
Second, back in the early 1800's a woman wouldn't have used a last name of Knutsson; that's a patronymic name reserved for men (son of Knut). Since Sigrid was born to Knut Jonsson, I believe she was known as Sigrid Knutsdotter (daughter of Knut) for most of her life, if not all of it.
Third, Olof Svensson born in 1840 probably went by the patronymic Pehrsson for part of his life, but as the patronymic tradition came to an end during the late 1800's, he may have changed that to Svensson later in life, assuming the name of his father has been correctly recorded here.
Fourth, spelling of names vary a lot in old records, depending more on the habit of the writer than on any express intent on the part of the bearer. The names Pehr and Pehrsson are today almost exclusively spelled Per and Persson, and those latter forms are also recommended for normalized spelling in genealogical research. Swedish spelling of Anne would in those days have been Anna (today we have a lot more forms of the name in popular use). Gölin is an old Swedish name that isn't very common today.
Someone with access to Brunflo records will have to assist you in order to verify these notes, but as you have several precise dates and names, it looks like a straightforward task. Doing so should resolve the confusing contradictions I have pointed out here.