Johanna is listed as "Ersdotter Johanna Elisabet fosterbarn" which translates into daughter of Er[ik], foster child. The mother in the family is Kristina Lovisa Karlsdotter, which means that she can't be sister of neither Erik Olhsson nor Anna Lisa Andersdotter, the parents of Johanna. If related to Johanna, it must be in some other way. And the same goes for Gustaf.

One more interesting thing is the notation "pl. för vådaskott" for Johanna. The "pl." must be short for "pliktat" which translates into "punished" and vådaskott is something like "a shot by accident". She has apparently shot and hurt somebody by accident and has been sentenced to pay som fines!