Despite her general hatred to muggles Bellatrix is actually very fond of most magical creatures, especially House elves.
This is because she was practically raised by them. With her parents never around except for the worst moments the elves of the house were the ones that took care of Bellatrix- she views many as genuine family.
It was actually her that convinced (read: pressured) Voldemort into accepting and recruiting magical creatures with the promise of freedom.


This Bellatrix? I don’t think so.