Yes, the script defies logic. That is why what you have to do is so counter-intuitive.
The kids will not find this easy, and that is the sad part about the choices your W is making. That is why it is so important that you spend time with them and really build strong bonds with them at this time. Do fun things, talk with them about what is going on in their lives, stay connected. They will need your strength and steadiness in the next while. Answer their questions honestly but without going into details they don't need to know. They will respect you for being there for them and doing what you can to save this M and the family.
Largely thanks to your guidance...