I think this is going to be an issue of semantics cause for one, Sylvanas hasn't murdered anyone directly except for Saurfang and Zelling in recent storylines and then there's the issue that deaths condemned as a result of war are still effectively killed by whoever ordered the war regardless of their intent in the war.
Dialing it back to being different because one wants pointless deaths is fine... but LEAD with that instead. Children have been murdered and killed because others wanted to assert their dominance and others wanted to make sure they were safe from future harm, the context of these different ideas of 'killing chilrden' can be very different.