I feel like in DoDA, Allarielle was using a bow for long range stuff, and otherwise was using her powers to like, banish Dark Magic or form big shields or healing and such, things like the Shield of Thorns spell on allied troops. At most, if she uses her cleansing powers to banish corruption and daemons and the like, that's not quite killing. If zooping corruption happens to make something no longer function in the material realm, that's not really killing 'em directly with Isha power That sounds reasonable to have happened. Like, if it really came down to it, throwing hands or beating someone to death with her staff would still not be the same thing as using Isha's divine powers to kill.
Yeah, I would tend to agree that banishing daemons and unbinding undead doesn't count as killing.
And, like, "The Everqueen cannot kill people with Isha's power" is not any kind of objective truth, in the Armybooks she is explicitly described as being able to kill anyone with even the slightest bit of corruption in them at a touch, manifesting ingame as her having Heroic Killing Blow against the Forces of Destruction.
However, in the novel Sons of Ellyrion, she is described as only being able to revert a Chaos Lord and his Hellsteed back into their ordinary, untainted forms, and when Slaanesh gets jealous and twists the Chaos Lord into a Spawn, she cannot destroy it because no matter how corrupted it is still alive, and it is anathema to the nature of Isha to take a life, so she just steps back and lets the protagonist Mage deal with it instead.
I just went with the novels over the Armybooks in this instance because I think that's cooler and more fitting. It emphasizes just how powerful the Everqueen is, that she can outright revert and remove the blessings of Chaos, a feat I don't recall seeing
anywhere else in the entirety of Warhammer Fantasy, which really serves to emphasize that here is the mortal avatar of a Goddess with a capital G, that Chaos are not the only ones with divine backing and their power is not infinite or impossible to overcome.
But such power also comes with limitations, because gods are beings of the Aethyr, shaped and given form by their own narratives. Isha can no more use her power to take a life than Tzeentch can be honest. The Everqueen cannot use Isha's power to kill, not even a Chaos Spawn.
And that's much more interesting to me than Isha just being able to do whatever.