Welcome to Wikitree, Roger!
Right now you are still a Guest Member, which does not give you the ability to add to any profile other than your own, though you can post a Comment on Susanna Elisabeth Wessels profile (see https://www.wikitree.com/wiki/Help:Membership).
If you want to edit the profile, your options are either to have the profile manager (Hermanus Wessel) add you to the Trusted List (there is a link on the profile allowing you to send him a private message), or to upgrade to being a Wiki Genealogist (which involves signing the Honor Code).
