Building Wordpress "Wiki" / "Ancestry" Website - Need Plugin and/or Theme Suggestions


First time forum user here. I need some help figuring out how to build a wordpress-based (ideally) wiki/ancestry/family tree type website for a client. It’s usually pretty easy to find plugins for any project on this site but this one has me stumped - any help would be greatly appreciated.

Client would like to build site for people of his nationality in a small city (400k people) - I guess they are a tight-nit group of people and he envisions a website where these people can follow up on members family tree. Also would use to post meet-up events and blog posts.

The part I’m struggling with is that they need an easy way for members of this community to sign up or make a “page” or “account” containing a short biography, some photos, and family connections. These pages would need to be editable by other members in case they pass away they can add a “died” date. Sort of like wikipedia. And we need modification history in case someone changes something inaccurate we can revert back.

They also need to be able to add connections to other members that would show up on this page with a “relationship description” and link to that connections page.

This theme “Wikiology” has the general look and feel:

But I need help coming up with the most efficient plugin(s) to handle the “wiki” functions, the “family tree” / connections part, and make it all simple for possibly older users. Also searchable by name but ideally pagenated alphabetized search (eg. click on letter “G” and all last names starting with G show up on a series of pages)

Hoping someone has a suggestions for wordpress so I don’t have to build this from scratch. Any advice would be greatly appreciated!