To edit a profile, click the green "edit" tab and you can edit the name, birth, and death information here, as well as relationships and the biography/sources.
You can add source citations to the profile either by listing them in the Sources section or by using in-line references after a fact in the biography (use the "C" button in the toolbar to automatically create the <ref> tags). See Help:Sources.
It is pretty simple to cite FamilySearch sources, you can simply click the "copy citation" button on any FamilySearch record page and then paste it into WikiTree. The WikiTree Sourcer browser extension also easily creates source citations for numerous websites (not Digitalarkivet though). I created a page for some suggested source citation formats for the Digitalarkivet website here.
Or if you prefer, I can add the sources to her profile for you.
Since you are the profile manager, you are the only one who can edit Minnie's last name at birth. Her last name should be "Mikkelsdatter" like Aksel mentioned above, and her father Mikkel's last name at birth should be "Amandsen" and her mother Anna's last name at birth should be "Andreasdatter".