While this is happening Kagha is over the top in her racist bigotry and seems to regret not killing Arabella if you talk her out of it. Then when she actually does kill her she has the "cringe" animation before going back to being racist. It makes no sense.
Because she's somewhat conflicted and not "all in" on evil yet. Its one thing to have hate and anger, and another thing to see a dead kid. After the deed is done, she's stuck to doubling down on the behavior or admit she was wrong.
Have you redeemed her yet? She thanks you for pulling her back from the brink and reflects on what she almost did.