Sacrificing your children for your own selfish pursuits isn't a "girl power" theme; it's quite the opposite.
I suggest re-reading the books for a fourth or fifth time.
Nothing I have seen in the series suggests to me that any of the women coming into power have selfishly sacrificed their children for their own gain. And I have not suggested that any of them have done so. Cersi did not want ANY of her children to die. Daenerys sure as hell did NOT want her son to die. Sansa and Yara will come into power eventually, but as yet, neither of them have children. Margaery would not have wanted to sacrifice a child for personal gain. The only one who was in to child sacrifice was the Red Witch, but it was someone else's child which was sacrificed.