I don't understand this about Mapleshade

I've recently finished Mapleshade's Vengeance, and everyone might know that she killed Appledusk, But Mapleshade went for Reedshine instead, saying " Appledusk is mine ", But still not feeling any guilt or smth after mis-landing her blow on Appledusk and eventually killing him; I don't understand how she said 'Appledusk is mine ' but still hated him, Did I just made a mistake?