The one who is the author of all life in the first place has every right to take it, no matter what the age or circumstance.
Because I believe none of those first born children under the age reason have actual sin, I also believe they in a better place. For the Egyptian adults it was meant to be a curse that would lead them to repentance, as well as liberate God’s chosen people, the Jews.
There are people of all ages that die every day. God has full authority over every birth and every death, just as He had a say with these first sons.
As in every pain and suffering, God desires to bring about good. And ultimately, this is what happened.
