"Delilah" is a bit of a work in progress at the moment; I've had the rough idea bouncing in my head for a while, but the finer points are still being hammered out. Toss in that she's a deceiver, liar, and certified headcase, and what she tells people might very well clash with what she's said before. Here, at least, are the points that are clear:
Hojo is "the Professor", obeyed, feared, hated. Unlike Aerith in the game, she did not raise any sort of protest when Cloud lifted his sword against him in Costa Del Sol.
Ifalna is a distant memory of the goodness she used to believe in.
Elmyra is the focal point of this AU. Her husband returned on leave like he was supposed to, so she was not there at the train station when Aerith was weeping over her dying mother.
Tseng found the young girl in the slums weeks after the escape, starved, injured, terrified and near ready to give up and die. He easily convinced her to come back to the safety she'd known in the labs and checked on her often afterwards, encouraging her in his own strange way to regain her health. Came into conflict with Hojo later over experiments being performed on Aerith and was murdered when she was fourteen. His death was a huge hit to her sanity and is likely the dividing point between "Aerith" and "Delilah".
Due to Tseng's demise, Reno is director of the Turks in this Aerith's time.
Sephiroth is "Brother", and the one who named her "Delilah". She holds him in the highest esteem and believes that he deserves to become a god, willingly becoming his instrument (though this decision may not have been entirely her own).
Zack may or may not be remembered; they met in the lab for only a few fleeting minutes. Zack was horrified that a person was being kept there, but both her behavior at the time and a convenient explanation later convinced him that because of her mental illness, she was receiving far better treatment in the labs than she would ever find on her own. That her mental illness arose from her experiences in the lab was never mentioned, of course.
Jenova is important to her, although what she considers Jenova to herself hasn't been determined yet. "Delilah" was injected with Jenova cells around age eighteen, greatly increasing her spellcasting potential; she does not require materia for low to mid-level spells. Was typically kept in magic-suppressing restraints for this reason. Delilah and Jenova both escaped in the Shinra building massacre.
Red XIII is despised, along with any animal that even remotely reminds her of him.
Cloud is beloved, at least to his face. He is, of course, trying to stop her Brother, which is a huge mistake in Delilah's book, and she is along with him for the ride to sabotage anything that might encourage him to remember who he truly is and to make him emotionally dependent on her alone. However, she has grown...strangely fond of him; amusement at her broken plaything mixed with pity for his ignorance and gratitude for his kind gestures, and she is now quite possessive of him. Still, Brother will be obeyed--and who knows? Perhaps in the end, Cloud will see how he was wrong and be happy for his loss.
Tifa is strongly disliked, as being Cloud's "childhood friend" makes her the most likely to ruin Brother's plans for him. Not to mention that Cloud is her toy. How well she actually knows Tifa is undetermined.
Marlene is completely unknown; the young girl died in Seventh Heaven when the plate was dropped. ...Sorry, Barret.
Anyone not on this list is completely up in the air right now.
Also, Aerith's place in time is roughly equivalent to when the group traveled to the Temple of the Ancients.