。
She got angry at being called a coward.
Literal
She [topic-は] coward [labeled-呼ばわりされて] was-angered.
~呼ばわり ('labeling someone as') is one of those sharp little Japanese suffixes specifically reserved for unfair or pejorative naming: 馬鹿呼ばわり ('called a fool'), 嘘つき呼ばわり ('called a liar'). Always paired with someone resenting the label. 立腹する ('to grow angry') is the formal Sino-Japanese verb for anger — slightly elevated compared to the everyday 怒る. The combination produces a literary, almost newspaper-headline feel.