I can't believe people are still talking about Nicole trying to kill herself. Like...the game is called "A Mother's Love" she's kinda an integral part of the story. It's not the end of the game yet...LOL, that should be the end of that discussion. It was left ambiguous at the end too create a talking point, but anyone with half a brain should realize its not over yet.
If someone was going to commit suicide, I don't think they would pack their bags too the spot where they were going to die. Also she had a smile on her face, Orb would have changed her expression to a sad face too make it more obvious if that were the case.
I have a theory that she went too swim because she hasn't felt this young and "alive" in years since she mentioned she hasn't been to the beach since Chloe was young, so now she's here taking a midnight swim butt naked to embrace the night, she also feels guilty thus she decides too leave early without the MC (the only reason too explain the packed bags).
MC will find her and they have another deep chat under the starlight how she cannot carry on like this and how her guilt is overpowering but she can't seem to resist the MC and they have "a lot" too talk about when they get home. Remember this is the first time Nicole gave back to MC, SHE fucked HIM this time around. A lot is going through Nicole's head, the swim was a cleansing and a detox from the nights events.