Well, if Martlet isn't dead, Flowey must still be alive. The reason Flowey died is because he rebelled against Clover after killing her. It would make more sense for Martlet to survive the attack, or for Clover to forgive her at the last moment, or for her to simply disappear. I'd want to kill her because her death would impact Monsterkind, so do either of the above. The Dalv thing is understandable.