I respectfully disagree, I do not feel that stunning is humane, nor necessary. If you choose to feed live, and do so following the recommended guidelines for feeding live, there should be no problems for her snake to take care of the prey on its own.
Pre-scent for 20-30 minutes, drop prey at opposite end of enclosure from snake (allowing snake to hunt from their hide), and remove prey within 30 minutes if the snake has no interest. Those basic guidelines have worked for me and countless other live feeders that find stunning completely un-necessary.