There's several options.
You can add yourself as manager on any profile within your Family Group.
Being a Collaborator with existing profiles will improve your edit rights.
You can request management of any profile.
https://help.geni.com/hc/en-us/articles/229704427-Who-is-included-i...
https://help.geni.com/hc/en-us/articles/229705467-Who-are-Collabora...
https://help.geni.com/hc/en-us/articles/229703887-How-can-I-request...
There is some help available, but may be a bit hard to find.
There are some links on this project https://www.geni.com/projects/Nederlandse-handleiding-GENI-voor-Dummies/13048 (English version bottom of the page)