Err... no... >.>. "Spawn of the devil", think towards that direction... A "child" =/= automatically innocent in her book, and if it was the result of a rapist human/sinner... that, by her twisted standards, would automatically equate it as evil.
To make things simple: Luna is horribly biased in her judging on the "Worth of Existence", and highly whimsical at that. Were she to be raped and become pregnant with the rapist's child as a result, she would most likely used twisted logic to "define" the unwanted child as "evil". And then use that as "proper reason" to kill the child.
(I think that's the proper explaination for it, just woke up and I'm groggy as hell...)