Fridge Brilliance: In Chapter 25, Veronica gets the living shit bullied out of her, which she stoically takes in stride, without so much as a complaint, let alone her usual way of doing things. She tells Fran "Everyone's so nice!" At first it looks like the scene is just a quick joke, but after a while, it dawns on you - Veronica was made as a bodyguard and before this, had always been surrounded by people who were trying to kill her. Compared to the shit she's lived through, even the worst schoolyard bullying is small potatoes.
It's never explicitly stated why the Professor abandoned Veronica, but it's later said that the people trying to kill the Professor eventually gave up trying to get past Veronica and started attacking the lab instead. She did her job too well and so, since he didn't need her anymore, he abandoned her.