the 2 kids that were tied to Tony? They did what she said, weren't immoral(their parts weren't big enough, anyway) and really didn't do anything to piss her off. So why were they killed? Bigger bodycount and less survivors is my guess.
KABLAM! NUCLEOID WAR!
She's a psychopath. She just felt like it, I'm guessing.
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I can't help being a gorgeous fiend. It's just the card I draw!-Lestat
Angela's reasoning for wanting Anita and Greg dead were weird, and it showed that she became lazy with her motivations later on. For Cindy, it was because she was a fornicator and a drug user (not to mention a racist); and for Herman it was because he was a pervert and so on.
But Anita and Greg...because they were boring? I don't remember them having any lines (if they did, they had less than five) or having any involvement with anything going on. But as others said, she's a psychopath and she probably just felt like it. And as one person said, you could be the nicest person--and Angela could still find a reason to want you dead. The only exception I could think of would be Molly, but even then where she is we don't know.
"I'll go,because I am Cinema!" - Ben (Man Bites Dog)