At the start of the game, it's shown Danielle respects Felix/Sophie's relationship & them as teachers a lot. I guess for me, it'd be weird for her to start seducing Felix out of nowhere, unless her values have been corrupted, or she has hard evidence that Sophie is cheating on Felix. Or both.While I didn't say Ms. Page I did have the characters right. There is the scene were Ms. Page calls Felix and he is distracted. I felt that would be a perfect time to show him distracted with Danielle, who could be very similar to Zack but more subtle in a nerdy unassuming girl that Danielle presents.
If she gets corrupted by Nate, I could see Zach trying to use her as a honeypot on Felix. Basically to show Sophie that Felix can also be unfaithful, and give her more reason to invest more in Zach. But if she's uncorrupted and finds out about the affair, I don't see why she wouldn't either confront Sophie, or talk to
Felix, based on what we've seen of her character.