It's fine if you dislike a character, Path Light. Not everyone will like the same characters. And it's fine if you want to talk about why you dislike them. But there's a line between discussion and bashing.
For example, instead of talking about how you want to make her pay for what she did to the Extreme Dinosaurs, say something like "If she were to ever to apologize for what she did, I have doubts the Extreme Dinosaurs would be so forgiving. Given all she did, they may just ignore her apology."
That sentence still gets across your point of how the Extreme Dinosaurs would likely not be forgiving but it's worded in a more mature, non-bashing manner.
Again, it's fine you hate Rebecca. But you already made it clear multiple times; there's no need to constantly bash her. Character Discussions are that, discussions, not an outlet to vent how much you hate a character and discuss things you'd do to them.