Ah - I didn't see the messages about what was or was not proved when I just posted.
Thoraway is right. When we are seeking information, we get very focused on what we don't have in our files - what we want to find out. The way to find out more, is always to begin with what we already know.
When you attempt to work with collaborators on a genealogy message board (and we love that you did) then you have helpers, but they are people who know nothing about your family.
The first step is to ground us in what YOU already KNOW!
We found a Marie Larsen b 08 Dec 1888 in Fredrikstad to Ole Christian Larsen and Josefine Nathalie Knudsen. Is that your great-grandmother, or not? Maybe you do not know?
The family records now being posted belong to the Marie above. Whether she is your Marie, we don't know. We could check it out - but what a lot of research that would be! And what a waste of work, when you already have the needed research, or so it seems.
In other words, you told us this is your family - not vice versa. Sorry if that was confusing.