important thing to note about the JELI (aka Ifalna, Lucrecia and Jenova escape Shinra and Elmyra gets a disaster polycule) AU is that in it Hojo is Sephiroth's father when he is born. and I say "when he is born" because the moment they are able to start exerting control over Sephiroth's cells, Jenova just edits all Hojo's genes out and fills them in with her own entirely out of spite
Logically i think this would be a slow process that starts when Sephiroth is a pretty young baby and Jenova just does it from a distance but I also really like the scenario of Lucrecia sitting on Elmyra's porch, watching her alien wife and their son garden. Jenova puts its hand on Sephiroth's shoulder for a second, and he flinches a little bit the way someone does when they get a static shock. They go back to gardening until Aerith comes out and wants to play with her brother, at which point Jenova slinks back to Lucrecia and sits next to her.
Lucrecia smiles and nudges Jenova, tells her, "It's nice seeing you two get along."
"I am his father now."
"...what?."
"What."
