2 global variables.
On start of layout (or some other trigger), set global variable 1 to family.count
Every tick, with condition (C) family.boolean=true, set global variable 2 to family.pickedcount
Compare 2 variables, if global variable 1 = global variable 2, end turn
You should see global var 1 as the total family members, you can set this once if the number of enemies doesn't change or at random intervals if the number of enemies will change. Global var 2 should be increasing as the boolean becomes true for the instances. Run it in debug to make sure it's acting correctly.