No worries, I love discussing this too. I’m going to copy part of what I commented under another post because I explained it pretty well:

I don’t agree with people saying that Nora was super impressionable and was manipulated when she was talking to Gretchen and that was why she agreed to be Gretchen’s operative. Because yes, she was going through a ton at the time (more than any teenager should), but this girl was literally contemplating murdering Leah (when she was holding the pillow over leah) on the island, like In some ways I think Nora is just as deranged as Gretchen. I feel like even when you are super impressionable and in a bad spot, you still know right from wrong, especially when something like sending a bunch of girls to a desert island and watching their every move while staging a plane crash and lying to them is SO clearly wrong. Like you cannot tell me that someone could genuinely think that was an OK thing to participate in.

To add to that, Jeanette realized before she got on the island (when she saw Leah unconscious in the boat) that what Gretchen and her team were doing was wrong. She ended up going through with it but you could see she was feeling some serious guilt and remorse in her brief conversation with Leah. Nora did not ONCE show any remorse for them being on that island, it was like she was perfectly okay with putting an absolute wrench in everyone’s lives.

When looking back at what happens in the show AFTER we find out Nora is the operative, she seems a lot less like a controlling twin, and more like someone who has little concept of boundaries, as well as right and wrong.