the author is grandstanding from an unprincipled stance. Israel can choose which families are harboring Hamas members and decide which houses to bomb or just bomb everything.
Hamas could also surrender after losing the war they started, at any time, and stand trial for starting a war. Hamas can choose to stop using their children as shields at any time. Hamas is to blame for everything.
If a murderer hides in your home, or not, when you and your children are inside, whether you like it or not, you can be bombed, if said house is in Gaza.
If you live in the US or Israel, you would have hundreds of effectives for every house, instead of killing people in a ratio of 60 to 1 (and counting)
I understand your confusion. The author wrote this article for an audience that has the same background as her, ignoring that not everyone has the same information. So it ended up confusing for a lot of people.
Hamas could also surrender after losing the war they started, at any time, and stand trial for starting a war. Hamas can choose to stop using their children as shields at any time. Hamas is to blame for everything.