Here are some ideas for things the player could say and sayori could reply:
Player: Are you happy? Sayori: Knowing im here with you, of course im happy. I hope you are too.
Player: Hello Sayori: Hi there
Player: Do you miss mc? Sayori: Yeah... a little, but now im here with you, mc was only an A.I. I get to talk to a real person now!
Those were some of my ideas, hope this mod gets more updates/improvments.