@oristarA,
I have recommended that you learn to diagram (or parse) these sentences that give you so much trouble. It would help you.
I am born and raised in the US.
"Chastened by the waste represented by sickness-induced casualties that she had suffered in her recent war with China," could be an adverbial clause that modifies the verb of the sentence and tells "when."
Or it could be an adjective describing "she."
With that, I will not respond to your questions again.