Do snuff films actually exist? I can't imagine someone making a video about killing someone irl, and not getting caught and having it seized by the police. Why would anyone make public works of incriminating evidence against them just for anyone to see?
Good on her ex for escaping before she got too confident to become forceful. Also, since it's her first kill, and the fact it was an accident. I doubt she actually got rid of all the evidence. She'll be caught in month or less.
Man is the older sis smart. Played the long game until intimate physical contact became natural even when just "friends". I'm sure if she did this long enough they'd start kissing for the fun of it.