Awesome show, I saw the episode last night and have it on again now to rewatch.
Its weird, she says she wants to go to the beach, yet she lives in an apartment in NYC so should know there isnt a beach nearby, shouldn't she?
She then just says the river will be fine, but cant be more specific than uptown.
Its kind of like she was from out of town, wasnt really her apartment.
She said "he was ok" about her dad. Naz assumes this means that her dad has died, but she doesnt say anything more about it. It could be she has already decided to kill herself, hence is talking in the past tense.
She then says "do you ever wish you could transport yourself, like, something bad happens here and youre over there?"
She then says she cant be alone tonight.
Like she needed to have someone at her place.
She gives him heaps of drugs - this was to deliberately get him to fall asleep.
When they play the knife game, she enjoys being stabbed.
My theory is that she has asked someone to kill her, by being stabbed. To get someone to do this, she frames Naz. The way they repeatedly show the deer too, its like they were trying to say someone was watching them.
The person who killed her was the motorbike rider. The rider was watching Naz to see his reaction to the whole thing.