Mab absolutely thinks differently about Maeve's death. For one, Mab is the cold and logical one in direct contrast to Titania's hot-blooded emotion. Of course she's going to think differently, and that's even before bringing in the fact that, again, Mab not only ordered it done but directly assisted in it.
You could argue that she's more directly responsible for the death than Murphy or Harry was.
Aurora's death to Titania and Maeve's death to Mab are two different circumstances, involving two different beings with diametrically opposed views and modes of operation, who take different roles in the deaths and are going to react differently.
So no, you can't say that because Hot Blooded Emotional Titania is angry at Harry (but ultimately doesn't actually harm him) for killing her daughter, Cold and Logical Mab who ordered Harry to kill Maeve and directly assisted Murphy in killing her is going to go to extreme length to punish someone for an act that she willfully and completely supported and assisted in.